Schedule I-Parent Company Financial Information (Notes To Condensed Financial Statements) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash dividends received from subsidiaries	$ 1,100,000,000	$ 747,000,000	$ 774,000,000
Dividends which may be paid to the parent company without prior approval by state regulatory authorities	970,000,000
Interest-bearing rate minimum	1.11%
Interest-bearing rate maximum	6.65%
Interest expense on subsidiary notes payable	1,000,000	1,000,000	1,000,000
Aggregate statutory capital and surplus in our state regulated subsidiaries	4,700,000,000	4,300,000,000
Tax adjustments, settlements, and unusual provisions			17,000,000
Regulatory Requirements [Member]
Dividends which may be paid to the parent company without prior approval by state regulatory authorities	$ 740,000,000