| Condensed Consolidating Financial Statements [Line Items] | |
| Net premiums written | 7.57B |
| Net premiums earned | 7.69B |
| Net investment income | |
| Total net realized gains (losses) including OTTI | |
| Losses and loss expenses | 4.27B |
| Policy benefits | 155M |
| Policy acquisition costs and administrative expenses | |
| Interest expense | |
| Other (income) expense | |
| Income tax expense (benefit) | 277M |
| Net income (loss) | 1.36B |
| Condensed Consolidating Financial Statements [Line Items] | |
| Net investment income | |
| Equity in earnings of subsidiaries | |
| Total net realized gains (losses) including OTTI | |
| Policy acquisition costs and administrative expenses | |
| Interest expense | |
| Other (income) expense | |
| Income tax expense (benefit) | 0 |
| Net income (loss) | -2.04B |
| Condensed Consolidating Financial Statements [Line Items] | |
| Net premiums written | 0 |
| Net premiums earned | 0 |
| Net investment income | |
| Total net realized gains (losses) including OTTI | |
| Losses and loss expenses | 0 |
| Policy benefits | 0 |
| Policy acquisition costs and administrative expenses | |
| Interest expense | |
| Other (income) expense | |
| Income tax expense (benefit) | 6M |
| Net income (loss) | 1.36B |
| Condensed Consolidating Financial Statements [Line Items] | |
| Net premiums written | 0 |
| Net premiums earned | 0 |
| Net investment income | |
| Total net realized gains (losses) including OTTI | |
| Losses and loss expenses | 0 |
| Policy benefits | 0 |
| Policy acquisition costs and administrative expenses | |
| Interest expense | |
| Other (income) expense | |
| Income tax expense (benefit) | -136M |
| Net income (loss) | 617M |
| Condensed Consolidating Financial Statements [Line Items] | |
| Equity in earnings of subsidiaries | |
| Policy acquisition costs and administrative expenses | |
| Interest expense | |
| Net income (loss) | 1.42B |