Earnings Per Share Schedule of Earnings per Share, Basic and Diluted (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Attributable to Parent	$ 147	$ 125	$ 95
Weighted Average Number of Shares Outstanding, Basic	75,333	75,275	72,790
Weighted Average Number Diluted Shares Outstanding Adjustment	17	16	62
Weighted Average Number of Shares Outstanding, Diluted	75,350	75,291	72,852
Earnings Per Share, Basic and Diluted	$ 1.95	$ 1.66	$ 1.31