| Pay vs Performance Disclosure | 12 Months Ended |
| Dec. 31, 2022 USD ($) $ / shares | Dec. 31, 2021 USD ($) $ / shares | Dec. 31, 2020 USD ($) $ / shares |
| Pay vs Performance Disclosure [Table] | | | |
| Pay vs Performance [Table Text Block] | The table below sets forth the Company’s Pay versus Performance disclosure: Year 1 Summary compensation table total for PEO Compensation actually paid to PEO 2 ($) Average summary compensation table total for non-PEO named executive officers Average compensation actually paid to non-PEO named executive officers 3 ($) Value of initial fixed $100 investment based on: Net income ($ in millions) Adjusted earnings, excluding reportable catastrophes, per diluted share 5 ($) Total shareholder return Peer group total shareholder return 4 ($) (a) (b) (c) (d) (e) (f) (g) (h) (i) 2022 8,372,281 4,698,824 3,239,523 1,610,161 100.90 130.65 276.60 13.61 2021 11,504,780 11,521,642 3,887,015 4,029,346 123.55 119.13 1,361.80 12.28 2020 11,855,966 12,716,846 3,622,320 4,040,321 106.09 81.72 441.70 10.49 | | |
| Named Executive Officers, Footnote [Text Block] | The PEOs were as follows: Keith W. Demmings in 2022; and Alan B. Colberg in 2021 and 2020. The NEOs were as follows: Richard S. Dziadzio, Robert A. Lonergan, Keith R. Meier, and Francesca L. Luthi in 2022; and Richard S. Dziadzio, Gene E. Mergelmeyer, Keith W. Demmings, and Francesca L. Luthi in 2021 and 2020. | | |
| PEO Total Compensation Amount | $ 8,372,281 | $ 11,504,780 | $ 11,855,966 |
| PEO Actually Paid Compensation Amount | $ 4,698,824 | 11,521,642 | 12,716,846 |
| Adjustment To PEO Compensation, Footnote [Text Block] | No awards granted to the PEOs during the period failed to meet vesting conditions. The table below details the adjustments made to the summary compensation table total to calculate the compensation actually paid to the PEO for each year: Year Summary compensation table total for PEO Stock awards and option awards columns of the summary compensation table Fair value of equity awards granted in year that remained outstanding and unvested as of year-end Change in fair value of the equity awards granted before year that are outstanding and unvested as of year-end Fair value of the awards that were granted and vested in year Change in fair value of all the equity awards granted before year that vested in year Aggregate change in pension benefits Pension “service cost” for year Compensation actually paid to PEO (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) 2022 8,372,281 (5,924,103) 3,671,173 (1,429,775) — 9,248 — — 4,698,824 2021 11,504,780 (7,273,698) 8,084,327 137,321 — (931,088) — — 11,521,642 2020 11,855,966 (7,326,852) 11,957,536 (243,381) — (3,526,423) — — 12,716,846 | | |
| Non-PEO NEO Average Total Compensation Amount | $ 3,239,523 | 3,887,015 | 3,622,320 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,610,161 | 4,029,346 | 4,040,321 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | No awards granted to the NEOs during the period failed to meet vesting conditions. The table below details the adjustments made to the summary compensation table total for the NEOs to calculate the average compensation actually paid to the NEOs for each year: Year Average summary compensation table total for non-PEO named executive officers Average stock awards and option awards columns of the summary compensation table Average fair value of equity awards granted in year that remained outstanding and unvested as of year-end Average change in fair value of the equity awards granted before year that are outstanding and unvested as of year-end Average fair value of the awards that were granted and vested in year Average change in fair value of all the equity awards granted before year that vested in year Average aggregate change in pension benefits Average pension “service cost” for year Average summary compensation table total for non-PEO named executive officers (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) 2022 3,239,523 (2,034,001) 1,251,264 (884,730) — 38,105 — — 1,610,161 2021 3,887,015 (2,040,398) 2,212,962 161,712 — (191,945) — — 4,029,346 2020 3,622,320 (1,757,398) 2,826,519 (24,686) — (626,434) — — 4,040,321 | | |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | The graph below represents the relationship between the CAP of the principal executive officer (the CEO, referred to as “PEO” in this section) and the NEOs with the Company’s TSR and a comparison of the Company’s TSR to the cumulative TSR of the peer group included in its Form 10-K: 1 Certain measures are non-GAAP. A reconciliation of these non-GAAP measures to their most comparable GAAP measures can be found in Appendix A hereto. | | |
| Compensation Actually Paid vs. Net Income [Text Block] | The graph below represents the relationship between the CAP of our PEO and NEOs with the Company’s net income: | | |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | The graph below represents the relationship between the CAP of our PEO and NEOs with the Company’s Company Selected Measure, Adjusted earnings, excluding reportable catastrophes, per diluted share: | | |
| Total Shareholder Return Vs Peer Group [Text Block] | The graph below represents the relationship between the CAP of the principal executive officer (the CEO, referred to as “PEO” in this section) and the NEOs with the Company’s TSR and a comparison of the Company’s TSR to the cumulative TSR of the peer group included in its Form 10-K: 1 Certain measures are non-GAAP. A reconciliation of these non-GAAP measures to their most comparable GAAP measures can be found in Appendix A hereto. | | |
| Tabular List [Table Text Block] | Tabular List of Performance Measures 1 Adjusted earnings, excluding reportable catastrophes, per diluted share Adjusted EBITDA, excluding reportable catastrophes Relative TSR Net earned premiums, fees and other income | | |
| Total Shareholder Return Amount | $ 100.90 | 123.55 | 106.09 |
| Peer Group Total Shareholder Return Amount | 130.65 | 119.13 | 81.72 |
| Net Income (Loss) | $ 276,600,000 | $ 1,361,800,000 | $ 441,700,000 |
| Company Selected Measure Amount | $ / shares | 13.61 | 12.28 | 10.49 |
| PEO Name | Keith W. Demmings | Alan B. Colberg | Alan B. Colberg |
| Additional 402(v) Disclosure [Text Block] | Refers to the S&P 500 Multi-Line Insurance Index included in “Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities—Stock Performance Graph” in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022, 2021 and 2020. | | |
| PEO [Member] | Adjustment, Stock Awards And Option Awards [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ (5,924,103) | $ (7,273,698) | $ (7,326,852) |
| PEO [Member] | Adjustment, Equity Awards Granted During The Year That Remained Outstanding And Unvested As Of Year-end [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 3,671,173 | 8,084,327 | 11,957,536 |
| PEO [Member] | Adjustment, Equity Awards Granted In Prior Years That Are Outstanding And Unvested As Of Year-end [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (1,429,775) | 137,321 | (243,381) |
| PEO [Member] | Adjustment, Equity Awards Granted And Vested In The Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 0 | 0 | 0 |
| PEO [Member] | Adjustment, Equity Awards Granted In Prior Years That Vested In Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 9,248 | (931,088) | (3,526,423) |
| PEO [Member] | Adjustment, Aggregate Change In Pension Benefits [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 0 | 0 | 0 |
| PEO [Member] | Adjustment, Pension Service Cost During The Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ 0 | 0 | 0 |
| Non-PEO NEO [Member] | Measure [Axis]: 1 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Adjusted earnings, excluding reportable catastrophes, per diluted share | | |
| Non-PEO NEO [Member] | Measure [Axis]: 2 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Adjusted EBITDA, excluding reportable catastrophes | | |
| Non-PEO NEO [Member] | Measure [Axis]: 3 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Relative TSR | | |
| Non-PEO NEO [Member] | Measure [Axis]: 4 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Net earned premiums, fees and other income | | |
| Non-PEO NEO [Member] | Adjustment, Stock Awards And Option Awards [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ (2,034,001) | (2,040,398) | (1,757,398) |
| Non-PEO NEO [Member] | Adjustment, Equity Awards Granted During The Year That Remained Outstanding And Unvested As Of Year-end [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 1,251,264 | 2,212,962 | 2,826,519 |
| Non-PEO NEO [Member] | Adjustment, Equity Awards Granted In Prior Years That Are Outstanding And Unvested As Of Year-end [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (884,730) | 161,712 | (24,686) |
| Non-PEO NEO [Member] | Adjustment, Equity Awards Granted And Vested In The Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Adjustment, Equity Awards Granted In Prior Years That Vested In Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 38,105 | (191,945) | (626,434) |
| Non-PEO NEO [Member] | Adjustment, Aggregate Change In Pension Benefits [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Adjustment, Pension Service Cost During The Year [Member] | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ 0 | $ 0 | $ 0 |
