Investments - Schedule of Sources of Net Investment Income Reported (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Schedule of Investments [Line Items]
Gross investment income	$ 587	$ 472	$ 1,167	$ 968
Investment expense	(62)	(47)	(123)	(92)
Interest and investment income	525	425	1,044	876
Fixed maturity securities, available-for-sale
Schedule of Investments [Line Items]
Gross investment income	448	336	880	655
Equity securities
Schedule of Investments [Line Items]
Gross investment income	4	4	9	8
Preferred securities
Schedule of Investments [Line Items]
Gross investment income	12	15	22	26
Mortgage loans
Schedule of Investments [Line Items]
Gross investment income	57	49	108	88
Invested cash and short-term investments
Schedule of Investments [Line Items]
Gross investment income	17	9	33	13
Limited partnerships
Schedule of Investments [Line Items]
Gross investment income	44	58	101	171
Other investments
Schedule of Investments [Line Items]
Gross investment income	$ 5	$ 1	$ 14	$ 7