Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Current Income Tax Expense (Benefit)	$ 83	$ (7)	$ 15
Deferred Other Tax Expense (Benefit)	(349)	(265)	850
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	351	257	(521)
Income Tax Expense (Benefit)	$ (85)	$ 15	$ (344)