Consolidated Balance Sheet Parentheticals (Unaudited at March 31, 2013) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheet (Unaudited at March 31, 2013)
Fixed maturities, available for sale, amortized cost	$ 60,578	$ 60,829
Equity securities, available for sale, cost	$ 446	$ 462
Common stock, shares authorized	1,750.0	1,750.0
Common stock, shares issued	376.4	377.4
Common stock, shares outstanding	376.4	377.4	389.8	392.8
Treasury stock, at cost, shares	376.7	372.3