Stockholders' Equity (Net Earnings Per Share) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders' Equity Note [Abstract]
Net Income Attributable to Parent	$ 205	$ 177	$ (161)	$ 169	$ 171	$ 79	$ 205	$ 164	$ 390	$ 619	$ 328
Weighted Average Number of Shares Outstanding, Basic									76.8	76.2	74.6
Weighted Average Number Diluted Shares Outstanding Adjustment									1.3	1.4	1.0
Weighted Average Number of Shares Outstanding, Diluted									78.1	77.6	75.6
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									2.1	1.6	3.0