Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 44,806	$ 45,241
Equity securities, cost	335	255
Mortgage loans on real estate valuation allowance	1	2
Securities pledged, amortized costs	1,739	1,824
Preferred stock, aggregate liquidation preference	$ 625	$ 325
Preferred stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	900,000,000	900,000,000
Common stock, shares issued	275,273,194	272,431,745
Common stock, shares outstanding	140,329,307	150,978,184
Treasury stock, shares	134,943,887	121,453,561
Common stock, par value	$ 0.01	$ 0.01