Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Income Tax Disclosure [Abstract] Net deferred tax asset Deferred Tax Assets, Net [Abstract] Deferred tax assets Deferred Tax Assets, Gross Deferred tax liabilities Deferred Tax Liabilities, Gross Net deferred tax liability Deferred Tax Liabilities, Net Components of the net deferred tax asset Components of Deferred Tax Assets and Liabilities [Abstract] Contingency reserves Deferred Tax Liabilities Contingency Reserves Amount of deferred tax liability attributable to taxable temporary differences from contingency reserves. Unearned premium reserve Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Unearned Premiums Reserve Unrealized (gain) loss on investments Deferred Tax Liabilities, Unrealized Gains on Trading Securities Accrued expenses Deferred Tax Liabilities Tax Deferred Expense Reserves and Accruals Accrued Liabilities Amount of deferred tax liability attributable to taxable temporary differences from accrued liabilities. Deferred policy acquisition costs Deferred Tax Liabilities, Deferred Expense, Deferred Policy Acquisition Cost Unearned ceding commissions Deferred Tax Assets, Deferred Expense, Unearned Ceding Commissions Deferred Tax Assets, Deferred Expense, Unearned Ceding Commissions Fixed assets Deferred Tax Assets, Property, Plant and Equipment Start-up expenditures, net Deferred Tax Assets, Start Up Expenses Net Represents the amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from net start-up expenditures. Change in fair market value of derivatives Deferred Tax Assets, Derivative Instruments Loss reserves Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Loss Reserves Nonvested shares Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Investments in limited partnerships Deferred Tax Liabilities, Investments Prepaid expenses Deferred Tax Liabilities, Prepaid Expenses Loss reserves - TCJA transition adjustment Deferred Tax Liability Tax Cuts And Jobs Act Deferred Tax Liability Tax Cuts And Jobs Act Organizational expenditures Deferred Tax Assets, Organizational Expenses Represents the amount before the allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from organizational expenditures. Share-based Payment Arrangement [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Maximum Maximum [Member] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Employee Employee [Member] Employee [Member] Director Director [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] First Vesting Period Share-based Payment Arrangement, Tranche One [Member] Second Vesting Period Share-based Payment Arrangement, Tranche Two [Member] Third Vesting Period Share-based Payment Arrangement, Tranche Three [Member] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Incentive Program Bonus Award Fiscal Year Performance Incentive Program Bonus Award Fiscal Year Performance [Member] Represents an incentive program covering bonus awards based on performance for previous fiscal year. Vesting Criteria [Axis] Vesting Criteria [Axis] Information about the type of vesting for share-based compensation awards. Vesting Criteria [Domain] Vesting Criteria [Domain] The types of vesting specified for share-based compensation awards. Time-Based Vesting Based On Service [Member] Represents a share based compensation award with vesting based on length of service. Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Share Units Restricted Stock Units (RSUs) [Member] Nonvested shares Restricted Stock [Member] Stock-based compensation Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vesting (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2013 Plan Essent Group Limited2013 Long Term Incentive Plan [Member] Represents the Essent Group Limited 2013 Long-term Incentive Plan (2013 Plan). Time and Performance- Based Share Awards Vesting Based On Service And Performance [Member] Represents a share based compensation award with vesting based on a combination of length of service and achievement of performance conditions. Performance -Based Vesting Based On Performance [Member] Represents a share based compensation award with vesting based on achievement of performance conditions. Certain members of senior management Certain Senior Management [Member] Represents some, but not all, of a team of individuals at the highest level of organizational management who have the day-to-day responsibilities of managing the entity. Performance period Share Based Compensation Arrangement by Share Based Payment Award Performance Period Represents the period over which a performance condition to the award is measured, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Net purchases of T&L Bonds Increase (Decrease) in Mortgage Guaranty Insurer United States Mortgage Guaranty Tax and Loss Bonds Represents, for a mortgage guaranty insurer, the increase (decrease) during the reporting period in the amount of investment in United States Mortgage Guaranty Tax and Loss Bonds issued by the Treasury Department for eligibility for certain tax deductions under enacted tax laws. T&L Bonds held as of end of period Mortgage Guaranty Insurer United States Mortgage Guaranty Tax and Loss Bonds Represents, for a mortgage guaranty insurer, the amount of investment in United States Mortgage Guaranty Tax and Loss Bonds issued by the Treasury Department for eligibility for certain tax deductions under enacted tax laws. Components of income tax expense Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Current Income Tax Expense (Benefit) Deferred Deferred Income Tax Expense (Benefit) Total income tax expense Income Tax Expense (Benefit) Effective Income Tax Rate Reconciliation, Amount Effective Income Tax Rate Reconciliation, Amount [Abstract] Tax provision at weighted average statutory rates Income Tax Reconciliation Income Tax Expense Benefit at Weighted Average Income Tax Rate The amount of income tax expense or benefit for the period computed by applying the weighted average income tax rate to pretax income from continuing operations. Non-deductible expenses Income Tax Reconciliation at Weighted Average Income Tax Rate Nondeductible Expense Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average income tax rate to pretax income (loss) from continuing operations attributable to nondeductible expenses. Excess tax benefits from stock-based compensation Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount Tax exempt interest, net of proration Income Tax Reconciliation at Weighted Average Income Tax Rate Tax Exempt Income Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average income tax rate to pretax income (loss) from continuing operations attributable to income (loss) exempt from income taxes. Other Income Tax Reconciliation at Weighted Average Income Tax Rate Other Adjustments Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average income tax rate to pretax income (loss) from continuing operations attributable to other adjustments. % of pretax income Effective Income Tax Rate Reconciliation, Percent [Abstract] Tax provision at weighted average statutory rates Effective Income Tax Rate Reconciliation at Weighted Average Statutory Income Tax Rate Percentage of weighted average statutory tax rate applicable to pretax income (loss). Non-deductible expenses Effective Income Tax Rate Reconciliation Weighted Average Statutory Income Tax Rate Non-deductible Expense Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average statutory income tax rate to pretax income (loss) from continuing operations attributable to nondeductible expenses. Excess tax benefits from stock-based compensation Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Percent Tax exempt interest, net of proration Effective Income Tax Rate Reconciliation Weighted Average Statutory Income Tax Rate Tax Exempt Income Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average statutory income tax rate to pretax income (loss) from continuing operations attributable to income (loss) exempt from income taxes. Other Effective Income Tax Rate Reconciliation Weighted Average Statutory Income Tax Rate Other Adjustments Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the weighted average statutory income tax rate to pretax income (loss) from continuing operations attributable to other adjustments. Total income tax expense Effective Income Tax Rate Reconciliation, Percent Capital [Abstract] Capital Stock Stockholders' Equity Note Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Indemnifications related to contract underwriting services Indemnification Agreement [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Amount paid for remedies (less than) Loss Contingency Accrual, Payments Renewal term (up to) Lessee, Operating Lease, Renewal Term Operating lease Operating Lease, Right-of-Use Asset Present value of lease liabilities Operating Lease, Liability Lease cost Lease, Cost Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Quoted Prices in Active Markets for Identical Instruments (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] U.S. Treasury securities US Treasury Securities [Member] U.S. agency securities US Government Agencies Debt Securities [Member] U.S. agency mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Municipal debt securities Municipal Bonds [Member] Non-U.S. government securities: Debt Security, Government, Non-US [Member] Corporate debt securities Corporate Debt Securities [Member] Residential and commercial mortgage securities Residential And Commercial Mortgage Securities [Member] Residential And Commercial Mortgage Securities [Member] Asset-backed securities Asset-backed Securities [Member] Money market funds Money Market Funds [Member] Estimated fair values and carrying amounts of financial instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Fair Value Debt Securities, Available-for-sale Total assets at fair value Assets, Fair Value Disclosure Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Shares Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Treasury Stock Treasury Stock [Member] Statement Statement [Line Items] Changes in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Stockholders equity, beginning of period Stockholders' Equity Attributable to Parent Issuance of management incentive shares Shares Issued, Value, Share-based Payment Arrangement, before Forfeiture Cancellation of treasury stock Treasury Stock, Retired, Cost Method, Amount Dividends and dividend equivalents declared Dividends Stock-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Net income Net Income (Loss) Available to Common Stockholders, Basic Treasury stock acquired Treasury Stock, Value, Acquired, Cost Method Stockholders equity, end of period Insurance [Abstract] Statutory Accounting Practices [Table] Statutory Accounting Practices [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Essent Guaranty Essent Guaranty Inc [Member] Represents information pertaining to Essent Guaranty, Inc. (Essent Guaranty), a regulated and licensed indirect wholly-owned subsidiary of the reporting entity. Essent PA Essent PA [Member] Essent PA [Member] Essent Re Essent Reinsurance Ltd [Member] Represents information pertaining to Essent Reinsurance Ltd. (Essent Re), a wholly-owned Bermuda-domiciled Class 3A Insurer licensed pursuant to Section 4 of the Bermuda Insurance Act 1978, which offers mortgage-related insurance and reinsurance. Dividends Restrictions Statutory Accounting Practices [Line Items] Statutory net income Statutory Accounting Practices, Statutory Net Income Amount Statutory surplus Statutory Accounting Practices, Statutory Surplus Balance Represents the amount of statutory surplus (stockholders' equity), as of the balance sheet date, using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country. Contingency reserve liability Statutory Accounting Practices, Statutory Contingency Reserve Liability Represents the amount of contingency reserve liability, as of the balance sheet date, using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country. Increase in contingency reserve Statutory Accounting Practices, Increase (Decrease) in Contingency Reserve Represents the amount of increase (decrease) in contingency reserve. Statutory capital and surplus Statutory Accounting Practices, Statutory Capital and Surplus, Balance Investments, Debt and Equity Securities [Abstract] Schedule of investments available for sale Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of amortized cost and fair value of investments available for sale by contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of realized gross gains and losses on sale of investments available for sale Schedule of Realized Gain (Loss) [Table Text Block] Schedule of fair value of investments in an unrealized loss position and related unrealized losses Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Schedule of net investment income Investment Income [Table Text Block] Realized gross gains Debt Securities, Available-for-sale, Realized Gain Realized gross losses Debt Securities, Available-for-sale, Realized Loss Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Internal Investment Grade Internal Investment Grade [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Credit Concentration Risk Credit Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Accounts Receivable Securities [Member] Securities [Member] Municipal debt securities Investments available for sale Debt Securities, Available-for-sale [Line Items] Fair Value Debt Securities Available For Sale Continuous Unrealized Loss Position [Abstract] Debt Securities Available For Sale Continuous Unrealized Loss Position [Abstract] Less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months 12 months or more Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Total Debt Securities, Available-for-sale, Unrealized Loss Position Gross Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] Less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 months or more Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Other Information Other Information [Abstract] Other Information [Abstract] Number of investment securities in an unrealized loss position Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions Concentration risk, percentage Concentration Risk, Percentage Other-than-temporary impairments Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings Other invested assets Equity Method Investments Fair value of investments deposited with insurance regulatory authorities Debt Securities, Available-for-sale, Restricted Fair value of the required investments on deposit in trusts Assets Held-in-trust Assets on deposit under reinsurance agreement Assets on Deposit Under Reinsurance Agreements Assets on Deposit Under Reinsurance Agreements Assets on deposit for the benefit of the sponsor Assets On Deposit For The Benefit Of The Sponsor Assets On Deposit For The Benefit Of The Sponsor Statutory Accounting Statutory Accounting Disclosure [Text Block] Represents the entire disclosure pertaining to the statutory accounting. Summary of nonvested Common Share and nonvested Common Share unit activity Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Schedule of portion of nonvested Common Shares earned based upon achievement of compounded annual book value per share growth Schedule of Shares Earned Unvested Performance Shares [Table Text Block] Tabular disclosure of shares earned for unvested performance shares. Schedule of compensation expense, net of forfeitures, and related tax effects recognized in connection with nonvested shares Share-based Payment Arrangement, Cost by Plan [Table Text Block] Lease cost: Lease, Cost [Abstract] Operating lease cost Operating Lease, Cost Short-term lease cost Short-term Lease, Cost Sublease income Sublease Income Total lease cost Other information: Lessee, Operating Lease, Description [Abstract] Weighted average remaining lease term - operating leases Operating Lease, Weighted Average Remaining Lease Term Weighted average discount rate - operating leases Operating Lease, Weighted Average Discount Rate, Percent Non-U.S. government securities Residential and commercial mortgage securities Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Fair Value Debt Securities, Trading and Available-for-sale Investment Secondary Categorization [Axis] Investment Secondary Categorization [Axis] Investments by Secondary Categorization [Domain] Investments by Secondary Categorization [Domain] Special revenue bonds Special Revenue Municipal Bonds [Member] A municipal bond whose debt service is payable solely from the revenues derived from operating the facilities acquired or constructed with the proceeds of the bonds. General obligation bonds General Obligation Municipal Bonds [Member] A bond secured by a pledge of the issuer's taxing powers (limited or unlimited). More commonly the general obligation bonds of local governments are paid from ad valorem property taxes and other general revenues. Considered the most secure of all municipal debt. Certificate of participation bonds Certification Of Participation Bonds [Member] Represents a type of financing where an investor purchases a share of the lease revenues of a program rather than the bond being secured by those revenues. Tax allocation bonds Tax Allocation Municipal Bonds [Member] Bonds issued in conjunction with a redevelopment project. The taxes pledged to their repayment come from the increase of assessed value over and above a pre-established base. The redevelopment creates this added value, known as the tax increment. Financial Financial Sector [Member] Financial Sector [Member] Consumer, non-cyclical Consumer, Non-cyclical Sector [Member] Consumer, Non-cyclical Sector [Member] Communications Communications Sector [Member] Communications Sector [Member] Consumer, cyclical Consumer, Cyclical Sector [Member] Consumer, Cyclical Sector [Member] Energy Energy Sector [Member] Energy Sector [Member] Utilities Utilities Sector [Member] Utilities Sector [Member] Technology Technology Debt Sector [Member] Technology Debt Sector [Member] Basic materials Basic Materials Sector [Member] Basic Materials Sector [Member] Industrial Industrial Sector [Member] Industrial Sector [Member] Percentage of debt securities Investment Owned, Percent of Net Assets Schedule of assets and liabilities measured at fair vale on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Nonvested Shares, Share Units Or DEU Nonvested Shares, Share Units Or DEU [Member] Nonvested Shares, Share Units Or DEU [Member] Nonvested Shares, Share Units Nonvested Shares, Share Units [Member] Nonvested Shares, Share Units [Member] Total fair value of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Total unrecognized compensation expense Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Expected weighted average period for recognition of expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Shares tendered by employees to pay employee withholding taxes (in shares) Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Compensation expense, net of forfeitures, and related tax effects recognized in connection with nonvested shares Share-based Payment Arrangement, Expensed and Capitalized, Amount [Abstract] Compensation expense Share-based Payment Arrangement, Expense Income tax benefit Share-based Payment Arrangement, Expense, Tax Benefit Earnings Per Share [Abstract] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Performance-based share awards Performance Shares [Member] EPS calculation Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Antidilutive nonvested shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Percentage of award issuable if current period end were end of contingency period Share-based Compensation Arrangement by Share-based Payment Award, Award Period to Date Vesting Rights, Percentage Percentage of vesting of share-based compensation awards if the end of the current reporting period were the end of the vesting period. Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Gain on the sale of investments, net Realized Investment Gains (Losses) Equity in net loss (income) of other invested assets Income (Loss) from Equity Method Investments Distribution of income from other invested assets Proceeds from Equity Method Investment, Distribution Depreciation and amortization Depreciation, Depletion and Amortization Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Amortization of premium on investment securities Investment Income, Amortization of Premium Deferred income tax provision Change in: Increase (Decrease) in Operating Capital [Abstract] Accrued investment income Increase (Decrease) in Accrued Investment Income Receivable Accounts receivable Increase (Decrease) in Accounts Receivable Deferred policy acquisition costs Increase (Decrease) in Deferred Policy Acquisition Costs Other assets Increase (Decrease) in Other Operating Assets Reserve for losses and LAE Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Unearned premium reserve Increase (Decrease) in Unearned Premiums Other accrued liabilities Increase (Decrease) in Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Net change in short-term investments Payments for (Proceeds from) Short-term Investments Purchase of investments available for sale Payments to Acquire Debt Securities, Available-for-sale Proceeds from maturity of investments available for sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Proceeds from sales of investments available for sale Proceeds from Sale of Debt Securities, Available-for-sale Purchase of other invested assets Payments to Acquire Equity Method Investments Return of investment from other invested assets Proceeds from Equity Method Investment, Distribution, Return of Capital Purchase of property and equipment Payments to Acquire Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Credit facility borrowings Proceeds from Long-term Lines of Credit Treasury stock acquired Payments for Repurchase of Common Stock Dividends paid Payments of Ordinary Dividends, Common Stock Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash at beginning of year Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash at end of period Supplemental Disclosure of Cash Flow Information Supplemental Cash Flow Information [Abstract] Income tax payments Income Taxes Paid Interest payments Interest Paid, Excluding Capitalized Interest, Operating Activities Reinsurance Disclosures [Abstract] Effect of reinsurance Effects of Reinsurance [Table Text Block] Schedule of coverages and retentions Reinsurance Retention Policy [Table Text Block] Schedule of VIE assets and maximum exposure Schedule of Variable Interest Entities [Table Text Block] Cover [Abstract] Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Entity Address, City or Town Entity Address, City or Town Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Address, Country Entity Address, Country City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Central Index Key Entity Central Index Key Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Net premiums written: Premiums Written, Net [Abstract] Direct Direct Premiums Written Ceded Ceded Premiums Written Net premiums written Premiums Written, Net Net premiums earned: Premiums Earned, Net [Abstract] Direct Direct Premiums Earned Ceded Ceded Premiums Earned Net premiums earned Premiums Earned, Net Stock-Based Compensation Share-based Payment Arrangement [Text Block] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table] Reinsurance Policy, Type [Axis] Reinsurance Policy, Type [Axis] Reinsurance Policy [Domain] Reinsurance Policy [Domain] 2015 & 2016 Vintage Year 2015 and 2016 [Member] Vintage Year 2015 and 2016 [Member] 2017 Vintage Year 2017 [Member] Vintage Year 2017 2018 Vintage Year 2018 [Member] Vintage Year 2018 2019 Vintage Year 2019 [Member] Vintage Year 2019 [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Radnor Re 2019-2 Ltd Radnor Re 2019-2 Ltd. [Member] Radnor Re 2019-2 Ltd. [Member] Radnor Re 2018-1 Ltd. Radnor Re 2018-1 Ltd. [Member] Radnor Re 2018-1 Ltd. Radnor Re 2019-1 Ltd. Radnor Re 2019-1 Ltd. [Member] Radnor Re 2019-1 Ltd. [Member] Radnor Re 2020-1 Ltd. Radnor Re 2020-1 [Member] Radnor Re 2020-1 [Member] Radnor Entities Radnor Entities [Member] Radnor Entities [Member] Other Reinsurance Other Reinsurance [Member] Other Reinsurance [Member] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items] Remaining Insurance in Force Reinsurance, Remaining Insurance In Force Reinsurance, Remaining Insurance In Force Remaining Risk in Force Reinsurance, Remaining Risk In Force Reinsurance, Remaining Risk In Force Remaining Reinsurance in Force Reinsurance, Remaining Reinsurance In Force Reinsurance, Remaining Reinsurance In Force Remaining First Layer Retention Reinsurance Retention Policy, Amount Retained Rollforward of accumulated other comprehensive income (loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Time-Based Share Awards DEUs Dividend Equivalent Unit [Member] Dividend Equivalent Unit [Member] Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding at beginning of year (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding at end of period (in shares) Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding at beginning of year (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding at end of period (in dollars per share) Statement of Financial Position [Abstract] Fixed maturities available for sale, at fair value (amortized cost: 2020 — $3,061,177; 2019 — $2,967,225) Fixed Maturities [Member] Short-term investments available for sale, at fair value (amortized cost: 2020 — $595,173; 2019 — $315,360) Assets Assets [Abstract] Investments Debt Securities, Available-for-sale [Abstract] Total investments available for sale Total investments Investments Cash Cash Accrued investment income Accrued Investment Income Receivable Accounts receivable Financing Receivable, after Allowance for Credit Loss Deferred policy acquisition costs Deferred Policy Acquisition Cost Property and equipment (at cost, less accumulated depreciation of $58,517 in 2020 and $57,639 in 2019) Property, Plant and Equipment, Net Prepaid federal income tax Other assets Other Assets Total assets Assets Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Liabilities Liabilities [Abstract] Reserve for losses and LAE Liability for Claims and Claims Adjustment Expense Unearned premium reserve Unearned Premiums Net deferred tax liability Deferred Income Tax Liabilities, Net Credit facility borrowings (at carrying value, less unamortized deferred costs of $620 in 2020 and $763 in 2019) Long-term Line of Credit Other accrued liabilities Other Accrued Liabilities Total liabilities Liabilities Commitments and contingencies (see Note 7) Commitments and Contingencies Stockholders’ Equity Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Common shares, $0.015 par value: Authorized - 233,333; issued and outstanding - 98,602 shares in 2020 and 98,394 shares in 2019 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Basic weighted average shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Dilutive effect of nonvested shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Nonvested Shares with Forfeitable Dividends Diluted weighted average shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic earnings per share (in dollars per share) Earnings Per Share, Basic Diluted earnings per share (in dollars per share) Earnings Per Share, Diluted Schedule of statutory net income, statutory surplus and contingency reserve liability Statutory Accounting Practices Disclosure [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of Operations and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Accounting Policies [Abstract] Recently Issued Accounting Standards Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Dividends Payable [Table] Dividends Payable [Table] Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Forecast Forecast [Member] Dividends Payable [Line Items] Dividends Payable [Line Items] Quarterly cash dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Quarterly cash dividends paid (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity Affiliated Entity [Member] Essent PA Essent Guaranty Of P A Inc [Member] Represents information pertaining to Essent Guaranty of PA, Inc. (Essent PA), a regulated and licensed indirect wholly-owned subsidiary of the reporting entity. Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Quota share reinsurance Quota Share Reinsurance Transaction [Member] Represents an agreement between an insurer and a reinsurer whereby the reinsurer pays an agreed-upon percentage of all losses the insurer sustains. Reinsurance for mortgage insurance coverage in excess of 25% Excess Mortgage Insurance Coverage [Member] Represents an arrangement to assume that portion of the risk retained by an affiliate that is in excess of 25% of the balance of any mortgage loan insured by that affiliate after consideration of other reinsurance agreements at that affiliate, in accordance with certain state law requirements. Insurance Premium Revenue Recognition Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Residential mortgage down payment percentage for which mortgage insurance is generally required (less than) Loans and Leases Receivable Consumer Mortgage Insured Down Payment Percentage Represents the percentage of the total sale price that a home buyer contributes in cash towards the purchase of a home for which mortgage insurance is generally required. Number of states in which the entity is licensed to write mortgage insurance Number of States in which Entity Operates Reinsurance percentage Reinsurance Retention Policy, Reinsured Risk, Percentage Reinsurance for mortgage insurance coverage threshold (in excess of) Reinsurance Retention Policy, Reinsured Risk, Percentage Threshold Threshold percentage of risk reinsured on insurance products per entity policy. Panel of Reinsurers Panel Of Reinsurers [Member] Panel Of Reinsurers [Member] Increase of margin component of reinsurance premium Risk Margin Increase After Optional Termination Date Risk Margin Increase After Optional Termination Date Compounded Annual Book Value Per Share Growth 13% Compounded Annual Book Value Per Share Growth Achieved 13 Percent [Member] Represents information pertaining to 13% compounded annual book value per share growth achieved. Compounded Annual Book Value Per Share Growth 14% Compounded Annual Book Value Per Share Growth Achieved 14 Percent [Member] Represents information pertaining to 14% compounded annual book value per share growth achieved. Compounded Annual Book Value Per Share Growth 15% Compounded Annual Book Value Per Share Growth Achieved 15 Percent [Member] Represents information pertaining to 15% compounded annual book value per share growth achieved. Compounded Annual Book Value Per Share Growth 16% Compounded Annual Book Value Per Share Growth Achieved 16 Percent [Member] Compounded Annual Book Value Per Share Growth Achieved 16 Percent [Member] Compounded Annual Book Value Per Share Growth 17% Compounded Annual Book Value Per Share Growth Achieved 17 Percent [Member] Compounded Annual Book Value Per Share Growth Achieved 17 Percent [Member] Minimum Minimum [Member] Compounded Annual Book Value Per Share Growth Compounded Annual Book Value Per Share Growth Rate Represents the compounded annual book value per share growth rate, expressed as a percentage. Nonvested Common Shares Earned Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract] Schedule of reconciliation of beginning and ending reserve balances for losses and loss adjustment expenses (LAE) Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] Debt Disclosure [Abstract] Debt Obligations Debt Disclosure [Text Block] Amortized Cost Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] Due in 1 year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Due after 1 but within 5 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Due after 5 but within 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Amortized Cost Due after 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Subtotal Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Amortized Cost Fair Value Due in 1 year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Due after 1 but within 5 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Due after 5 but within 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Fair Value Due after 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Subtotal Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Income Taxes Income Tax Disclosure [Text Block] Schedule of reconciliation of net income and weighted average common shares outstanding used in computations of basic and diluted earnings per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Term Loan Secured Debt [Member] Uncommited Line Uncommitted Line of Credit [Member] Uncommitted Line of Credit Credit Facility [Line Items] Line of Credit Facility [Line Items] Credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Credit facility, commitment fee rate Line of Credit Facility, Commitment Fee Percentage Amount outstanding, gross Long-term Debt, Gross Weighted average interest during period Debt, Weighted Average Interest Rate Schedule of lease cost and other information Lease, Cost [Table Text Block] Schedule of lease liability maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Incurred claims and claim adjustment expenses Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Favorable prior year development Prior Year Claims and Claims Adjustment Expense Reserve for losses and LAE, for prior years Liability for Unpaid Claims and Claims Adjustment Expense Prior Years Liability, as of the balance sheet date, for amounts representing estimated cost of settling unpaid claims for prior years under the terms of the underlying insurance policies, less estimated reinsurance recoveries on such claims. This includes an estimate for claims which have been incurred but not reported. Claim adjustment expenses represent the costs estimated to be incurred in the settlement of unpaid claims. Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Fixed maturities Short-term investments Short-term Investments [Member] Investment available for sale Amortized cost Property and equipment Property, Plant and Equipment, Net [Abstract] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Credit Facility Borrowings Subordinated Borrowings [Abstract] Unamortized deferred costs Debt Issuance Costs, Gross Stockholders’ Equity Stockholders' Equity Attributable to Parent [Abstract] Common shares, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common shares, authorized (in shares) Common Stock, Shares Authorized Common shares, issued (in shares) Common Stock, Shares, Issued Common shares, outstanding (in shares) Common Stock, Shares, Outstanding Statement of Comprehensive Income [Abstract] Revenues: Revenues [Abstract] Net premiums written Decrease in unearned premiums (Increase) Decrease in Unearned Premiums, Net Net investment income Net Investment Income Realized investment gains, net Other income (loss) Other Income Total revenues Revenues Losses and expenses: Benefits, Losses and Expenses [Abstract] Provision for losses and LAE Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Other underwriting and operating expenses Other Underwriting and Operating Expenses Represents the aggregate amount of costs incurred during the period, such as those relating to general administration and policy maintenance that do not vary with, and are not primarily related to the acquisition or renewal of insurance contracts and other operating costs, that are associated with the entity's normal revenue producing operation. Interest expense Interest Expense Total losses and expenses Benefits, Losses and Expenses Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Net income Earnings per share: Earnings Per Share, Basic and Diluted [Abstract] Basic (in dollars per share) Diluted (in dollars per share) Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) Net income Other comprehensive income (loss): Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Change in unrealized (depreciation) appreciation of investments, net of tax (benefit) expense of ($6,979) in 2020 and $7,951 in 2019 Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Total other comprehensive income (loss) Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Net Investment Gains (Losses) On Investments AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Before Tax AOCI Attributable To Parent, Before Tax [Roll Forward] AOCI Attributable To Parent, Before Tax [Roll Forward] AOCI before tax, beginning of period AOCI before Tax, Attributable to Parent Other comprehensive income (loss): Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] Unrealized holding gains (losses) arising during the period, before tax OCI, before Reclassifications, before Tax, Attributable to Parent Less: Reclassification adjustment for gains included in net income, before tax Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Other comprehensive income (loss), before tax Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent AOCI before tax, end of period Tax Effect AOCI Attributable To Parent, Tax [Roll Forward] AOCI Attributable To Parent, Tax AOCI tax effect, beginning of period AOCI Tax, Attributable to Parent Other comprehensive income (loss): Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract] Unrealized holding (gains) losses arising during the period, tax effect Other Comprehensive Income (Loss) before Reclassifications, Tax Less: Reclassification adjustment for gains included in net income, tax effect Reclassification from AOCI, Current Period, Tax Other comprehensive (income) loss, tax effect Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent AOCI tax effect, end of period Net of Tax AOCI Attributable to Parent, Net of Tax [Roll Forward] Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unrealized holding gains (losses) arising during the period, net of tax OCI, before Reclassifications, Net of Tax, Attributable to Parent Less: Reclassification adjustment for gains included in net income, net of tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Change in unrealized appreciation (depreciation) of investments, tax expense (benefit) Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent 2020 (April 1 through December 31) Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2021 Lessee, Operating Lease, Liability, Payments, Due Year Two 2022 Lessee, Operating Lease, Liability, Payments, Due Year Three 2023 Lessee, Operating Lease, Liability, Payments, Due Year Four 2024 Lessee, Operating Lease, Liability, Payments, Due Year Five 2025 and thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments to be paid Lessee, Operating Lease, Liability, Payments, Due Less: Future interest expense Lessee, Operating Lease, Liability, Undiscounted Excess Amount Investment Income [Table] Investment Income [Table] Components of net investment income Net Investment Income [Line Items] Gross investment income Gross Investment Income, Operating Investment expenses Investment Income, Investment Expense Net investment income Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Mortgage Insurance Linked Notes Mortgage Insurance Linked Notes [Member] Mortgage Insurance Linked Notes [Member] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Radnor Re Radnor Re [Member] Radnor Re [Member] Quota Share Reinsurance Quota Share Reinsurance [Member] Quota Share Reinsurance [Member] Mortgage Insurance Mortgage Insurance [Member] Mortgage Insurance [Member] Ceded premiums earned related to percent of risk on eligible single premium policies Reinsurance, Ceded Premiums Earned, Percent Of Risk On Eligible Single Premium Policies Reinsurance, Ceded Premiums Earned, Percent Of Risk On Eligible Single Premium Policies Ceded premiums earned related to percent of risk on all other eligible policies written Reinsurance, Ceded Premiums Earned, Percent Of Risk On All Other Eligible Policies Reinsurance, Ceded Premiums Earned, Percent Of Risk On All Other Eligible Policies Ceding commission, percent Reinsurance, Ceded Premiums Earned, Ceding Commission, Percent Reinsurance, Ceded Premiums Earned, Ceding Commission, Percent Profit commission, percent, maximum Reinsurance, Profit Commissions, Maximum Reinsurance, Profit Commissions, Maximum RIF ceded Risk In Force, Ceded Risk In Force, Ceded Amortization period Amortization Period Excess of Loss Portfolio Amortization Period Excess of Loss Portfolio Reinsurance retention policy, debt issued to cover insurance, term Reinsurance, Debt Issued To Cover Insurance, Term Reinsurance, Debt Issued To Cover Insurance, Term Schedule of components of income tax expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of reconciliation of difference between income tax expense and expected tax provision at weighted average tax rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of net deferred tax (liability) asset and components Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Earnings per Share (EPS) Earnings Per Share [Text Block] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Radnor Re 2019-2 Ltd. Radnor Re 2019-2 [Member] Radnor Re 2019-2 [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Total VIE Assets Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Maximum Exposure to Loss, On - Balance Sheet Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount On The Balance Sheet Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount On The Balance Sheet Maximum Exposure to Loss, Off - Balance Sheet Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Off The Balance Sheet Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Off The Balance Sheet Maximum Exposure to Loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss (Gain) Exposure, Amount Variable Interest Entity, Reporting Entity Involvement, Maximum Loss (Gain) Exposure, Amount Reserve for Losses and Loss Adjustment Expenses Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Reconciliation of the beginning and ending reserve balances for losses and loss adjustment expenses (LAE) Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Reserve for losses and LAE at beginning of period Less: Reinsurance recoverables Reinsurance Recoverable for Unpaid Claims and Claims Adjustments Net reserve for losses and LAE at beginning of period Liability for Unpaid Claims and Claims Adjustment Expense, Net Add provision for losses and LAE, net of reinsurance, occurring in: Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract] Current period Current Year Claims and Claims Adjustment Expense Prior years Net incurred losses and LAE during the current period Deduct payments for losses and LAE, net of reinsurance, occurring in: Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract] Current period Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year Prior years Net loss and LAE payments during the current period Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid Net reserve for losses and LAE at end of period Plus: Reinsurance recoverables Reserve for losses and LAE at end of period Loans in default at end of period Number of Loans in Default Represents the number of loans in default. Reinsurance Reinsurance [Text Block]