Investments - Realized Investment Gains and Losses and Change in Unrealized Investment Gains and Losses and Other Items (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Investment income:
Interest	$ 169	$ 140
Dividends	72	66
Other	7	7
Total	248	213
Less investment expenses	3	3
Total	245	210
Investment gains and losses, net
Change in allowance for credit losses, net	(9)	0
Other	20	1
Total	612	106
Equity securities
Investment gains and losses, net
Investment gains and losses on securities sold, net	(11)	(1)
Unrealized gains and losses on securities still held, net	613	106
Total	602	105
Fixed maturities
Investment gains and losses, net
Gross realized gains	0	1
Gross realized losses	(1)	(1)
Total	$ (10)	$ 0