Income Taxes (Income Tax Expense (Benefit)) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Contingency [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 9,000,000
Income tax (expense) benefit	19,000,000	50,000,000
Effective Income Tax Rate, Continuing Operations	53.00%	29.00%
Unrecognized Tax Benefits	66,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	16,000,000
Unrecognized Tax Benefits Resulting in Net Operating Loss Carryforward	50,000,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	13,000,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	$ 0