Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Securities available for sale, equity securities, cost	$ 17	$ 17
Securities held to maturity, fixed maturities, fair value	42,816	45,846
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)	667,620,000	667,046,000
Asset derivatives	523	488
Liability derivatives	358	837
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, fixed maturities, amortized cost	57,429	52,402
Securities available for sale, perpetual securities, amortized cost	2,582	2,524
Securities held to maturity, fixed maturities, fair value	42,576	45,610
Variable Interest Entity, Consolidated
Securities available for sale, fixed maturities, amortized cost	3,896	4,109
Securities available for sale, perpetual securities, amortized cost	475	463
Securities held to maturity, fixed maturities, fair value	240	236
Asset derivatives	107	106
Liability derivatives	$ 194	$ 207