CONDENSED CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
CONDENSED CONSOLIDATED STATEMENTS OF FINANCIAL POSITION
Fixed income securities, at fair value, amortized cost (in dollars)	$ 70,957	$ 71,915
Equity securities, at fair value, cost (in dollars)	3,777	3,577
Short-term, at fair value, amortized cost (in dollars)	$ 3,169	$ 2,336
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	900,000,000	900,000,000
Common stock, shares outstanding	468,000,000	479,000,000
Treasury stock, shares	432,000,000	421,000,000