Condensed Consolidated Statements of Financial Position (unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Fixed income securities, at fair value, amortized cost	$ 49,979	$ 45,370
Equity securities, at fair value, cost	2,393	4,253
Short-term, at fair value, amortized cost	$ 3,369	$ 4,174
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	82,000	81,000
Preferred stock, shares outstanding (in shares)	82,000	81,000
Preferred stock, value aggregate liquidation preference	$ 2,050	$ 2,025
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	900,000,000	900,000,000
Common stock, shares outstanding (in shares)	262,000,000	263,000,000
Treasury stock, shares (in shares)	638,000,000	637,000,000