Investments - Net Investment Income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 401,000,000	$ 385,000,000	$ 1,207,000,000	$ 1,289,000,000
Less: investment expense	17,000,000	19,000,000	52,000,000	54,000,000
Net investment income	384,000,000	366,000,000	1,155,000,000	1,235,000,000
Realized capital gains (losses)	(64,000,000)	(69,000,000)	(142,000,000)	(387,000,000)
Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	319,000,000	351,000,000	970,000,000	1,060,000,000
Investments in fixed maturities that did not produce net income	8,000,000		8,000,000
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	2,000,000	2,000,000	8,000,000	7,000,000
Mortgage loans on real estate
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	50,000,000	45,000,000	147,000,000	134,000,000
Realized capital gains (losses)	0	1,000,000
Policy loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	2,000,000	2,000,000	6,000,000	6,000,000
Short-term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	3,000,000	1,000,000	7,000,000	2,000,000
Other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	25,000,000	(16,000,000)	69,000,000	80,000,000
Realized capital gains (losses)	$ (64,000,000)	$ (69,000,000)	$ 0	$ 0