Condensed Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed income securities, at fair value, amortized cost (in dollars)	$ 58,945	$ 56,293
Equity securities, at fair value, cost (in dollars)	3,631	6,568
Short-term, at fair value, amortized cost (in dollars)	$ 5,671	$ 4,256
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)	81,000	92,500
Preferred stock, shares outstanding (in shares)	81,000	92,500
Preferred stock, shares aggregate liquidation preference (in shares)	$ 2,025	$ 2,313
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	3,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	900,000,000	900,000,000
Common stock, shares outstanding (in shares)	315,000,000	319,000,000
Treasury Stock, shares (in shares)	585,000,000	581,000,000