Investments - Interest and Investment Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Investments [Line Items]
Gross investment income	$ 673	$ 524
Investment expense	(62)	(46)
Interest and investment income	611	478
Fixed maturity securities, available-for-sale
Schedule of Investments [Line Items]
Gross investment income	447	332
Equity securities
Schedule of Investments [Line Items]
Gross investment income	8	8
Preferred securities
Schedule of Investments [Line Items]
Gross investment income	13	15
Mortgage loans
Schedule of Investments [Line Items]
Gross investment income	51	39
Invested cash and short-term investments
Schedule of Investments [Line Items]
Gross investment income	33	5
Limited partnerships
Schedule of Investments [Line Items]
Gross investment income	57	113
Tax deferred property exchange income
Schedule of Investments [Line Items]
Gross investment income	45	3
Other investments
Schedule of Investments [Line Items]
Gross investment income	$ 19	$ 9