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(Loss) AOCI Attributable to Parent [Member] Other assets Other Assets Common stock, outstanding (in shares) Common Stock, Shares, Outstanding Financial Instruments [Domain] Financial Instruments [Domain] Number of securities, less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Entity Central Index Key Entity Central Index Key Common stock: class A shares issued under stock plans, net of shares withheld for employee taxes (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans, Net of Shares For Tax Withholdings Stock Issued During Period, Shares, Employee Stock Purchase Plans, Net of Shares For Tax Withholdings Deferred tax asset Deferred Tax Assets, Gross [Abstract] Number of operating leases related to corporate headquarters and data center facility Number Of Operating Leases, Corporate Office And Data Center Facility Number Of Operating Leases, Corporate Office And Data Center 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Class A Common Class A [Member] Applicable premium Debt Instrument, Covenant Terms, Applicable Premium Debt Instrument, Covenant Terms, Applicable Premium Cash and cash equivalents (including restricted cash of $3,165 and $5,555 as of December 31, 2021 and December 31, 2020, respectively) Cash, cash equivalents and restricted cash, beginning of period Cash, cash equivalents and restricted cash, end of period Cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Shares issued from sale of stock (in shares) Sale of Stock, Number of Shares Issued in Transaction Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Year 8 Short-duration Insurance Contracts, Historical Claims Duration, Year Eight Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] Short-duration Insurance 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[Member] Cash and investments held with various state insurance departments Cash, Cash Equivalents, and Short-term Investments Common Stock Stockholders' Equity Note Disclosure [Text Block] Auditor Firm ID Auditor Firm ID Net cash used in investing activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Dividends, restriction with regards to capital surplus (in percent) Ordinary Dividends, Restriction with Regards to Capital Surplus This concept represents the maximum percentage of surplus as of the prior year that an insurer may pay out in ordinary dividends without prior approval of the Wisconsin Office of the Commissioner of Insurance under Wisconsin law. 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Financial Information of Registrant Reinsurance SEC Schedule, 12-17, Insurance Companies, Reinsurance [Text Block] Initial Reinsurance Coverage Initial Reinsurance Coverage Initial Reinsurance Coverage Financial Financial, Industry Group [Member] Financial, Industry Group [Member] 2018 QSR Transaction Two Thousand Eighteen QSR Transaction [Member] Two Thousand Eighteen QSR Transaction [Member] Depreciation and amortization Depreciation, Amortization and Accretion, Net Schedule of key inputs and assumptions in option-pricing model Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Name of Property [Domain] Name of Property [Domain] Common stock - class A shares, $0.01 par value; 85,792,849 and 85,163,039 shares issued and outstanding as of December 31, 2021 and December 31, 2020, respectively (250,000,000 shares authorized) Common Stock, Value, Outstanding Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Other operating expenses Other Expenses Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Current year Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year