Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Securities available for sale, equity securities, cost	$ 17	$ 20
Securities held to maturity, fixed maturities, fair value	42,761	54,841
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	1,900,000,000	1,900,000,000
Common stock, shares issued	666,009,000	665,239,000
Asset derivatives	620	345
Liability derivatives	447	934
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, fixed maturities, amortized cost	50,742	48,355
Securities available for sale, perpetual securities, amortized cost	2,766	3,654
Securities held to maturity, fixed maturities, fair value	42,521	54,554
Variable Interest Entity, Consolidated
Securities available for sale, fixed maturities, amortized cost	4,636	5,058
Securities available for sale, perpetual securities, amortized cost	500	559
Securities held to maturity, fixed maturities, fair value	240	287
Asset derivatives	135	191
Liability derivatives	$ 284	$ 399