Statutory Financial Information and Dividend Limitations (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statutory Financial Information and Dividend Limitations
Statutory net income (loss)	$ 382,000,000	$ (83,000,000)	$ (456,000,000)
Statutory capital and surplus	3,380,000,000	3,460,000,000
Deficit position used to determine payment of dividends	$ 62,000,000