Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Available-for-sale securities, at fair value:
Fixed maturity securities (amortized cost)	$ 85,834	$ 84,287
Variable interest entities' fixed maturity securities (amortized cost)	0	200
Equity securities (cost)	$ 263	$ 260
Stockholders Equity
Preferred stock - shares authorized (in shares)	10,000,000	10,000,000
Common stock - shares authorized (in shares)	800,000,000	800,000,000
Common stock - shares issued (in shares)	224,888,259	226,335,105
Common stock - shares outstanding (in shares)	224,888,259	226,335,105