Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Securities held to maturity, fixed maturities, fair value	$ 48,796	$ 37,520
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)	670,764,000	669,723,000
Asset derivatives	$ 1,963	$ 676
Liability derivatives	542	371
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, fixed maturities, amortized cost	65,121	56,903
Securities available for sale, perpetual securities, amortized cost	1,649	1,586
Securities available for sale, equity securities, cost	227	117
Securities held to maturity, fixed maturities, fair value	48,796	37,520
Variable Interest Entity, Consolidated
Securities available for sale, fixed maturities, amortized cost	4,878	3,739
Securities available for sale, perpetual securities, amortized cost	267	255
Securities available for sale, equity securities, cost	1,018	363
Asset derivatives	177	102
Liability derivatives	$ 117	$ 293