Long-Duration Insurance Contracts - Separate Account Liability Rollforward (Details) - USD ($) $ in Millions |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2025 |
Dec. 31, 2024 |
|
| Separate Account, Liability [Roll Forward] | ||
| Balance, beginning of year | $ 3,708.8 | |
| Balance, end of period | 3,863.3 | $ 3,708.8 |
| Variable Account Annuities | ||
| Separate Account, Liability [Roll Forward] | ||
| Balance, beginning of year | 3,708.8 | 3,294.1 |
| Deposits | 137.4 | 266.2 |
| Withdrawals | (146.4) | (290.3) |
| Net transfers | (19.6) | (21.1) |
| Fees and charges | (27.0) | (53.3) |
| Market appreciation (depreciation) | 210.1 | 513.2 |
| Other | 0.0 | 0.0 |
| Balance, end of period | $ 3,863.3 | $ 3,708.8 |
| X | ||||||||||
- Definition Amount of cash inflow to separate account liability for cash received for deposit. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in separate account liability from performance of investment. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount increase (decrease) in separate account liability from change, classified as other. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of decrease in separate account liability from policy charge. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Definition Amount of decrease in liability for separate account from withdrawal of funds. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of liability for variable contract in which all or portion of contract holder's funds is allocated to specific separate account and supported by assets held in separate account. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of transfer to (from) liability for policyholder account balance (to) from liability for separate account. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Details
|