Income Taxes (Income Tax Expense (Benefit)) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 50,000,000	$ 6,000,000
Effective Income Tax Rate, Continuing Operations	29.00%	40.00%
Unrecognized Tax Benefits	79,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	24,000,000
Unrecognized Tax Benefits Resulting in Net Operating Loss Carryforward	55,000,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	14,000,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 5,000,000