Investments and Cash - Equity in Net Earnings of Investees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Equity in earnings (losses) of investees	$ (39)	$ 94	$ 27
Fair Value Measured at Net Asset Value
Net Investment Income [Line Items]
Equity in earnings (losses) of investees		36	14
Equity Securities
Net Investment Income [Line Items]
Equity in earnings (losses) of investees	(39)	94	27
Cash dividends from subsidiaries	10	15	10
Equity Securities | AssuredIM Funds
Net Investment Income [Line Items]
Equity in earnings (losses) of investees	2	30	14
Equity Securities | Other
Net Investment Income [Line Items]
Equity in earnings (losses) of investees	$ (41)	$ 64	$ 13