Claim and Claim Adjustment Expense Reserves (Commercial - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - Commercial - USD ($) $ in Millions |
3 Months Ended | |
---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
|
Liability for Claims and Claims Adjustment Expense [Line Items] | ||
Commercial Auto | $ 0 | $ 9 |
General Liability | 0 | 0 |
Workers' Compensation | 0 | (13) |
Property and Other | 0 | 0 |
Total pretax (favorable) unfavorable development | $ 0 | $ (4) |