Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Securities available for sale, Equity securities, cost	$ 21	$ 22
Securities held to maturity, fixed maturities, fair value	52,540	46,383
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	1,900,000,000	1,900,000,000
Common stock, shares issued	664,532,000	663,639,000
Variable Interest Entity, Consolidated
Securities available for sale, Fixed maturities, amortized cost	5,262	4,822
Securities available for sale, Perpetual securities, amortized cost	899	1,532
Securities held to maturity, fixed maturities, fair value	311	566
Asset Derivatives	281	375
Liability Derivatives	474	531
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, Fixed maturities, amortized cost	41,699	40,534
Securities available for sale, Perpetual securities, amortized cost	4,383	5,365
Securities held to maturity, fixed maturities, fair value	$ 52,229	$ 45,817