Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Securities available for sale, equity securities, cost	$ 19	$ 19
Securities held to maturity, fixed maturities, fair value	$ 36,365	$ 38,497
Common stock, par value (in dollars per share)	$ 0.1	$ 0.1
Common stock, shares authorized (in shares)	1,900,000,000	1,900,000,000
Common stock, shares issued (in shares)	669,066,000	668,132,000
Asset derivatives	$ 752	$ 802
Liability derivatives	502	2,423
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, fixed maturities, amortized cost	55,684	55,365
Securities available for sale, perpetual securities, amortized cost	1,812	2,035
Securities held to maturity, fixed maturities, fair value	36,285	38,413
Variable Interest Entity, Consolidated
Securities available for sale, fixed maturities, amortized cost	3,446	3,020
Securities available for sale, perpetual securities, amortized cost	281	405
Securities held to maturity, fixed maturities, fair value	80	84
Asset derivatives	100	106
Liability derivatives	$ 322	$ 318