Income Taxes (Effective Income Tax Rate) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	35.00%
Income tax benefit at the federal statutory rate	$ 923	$ 1,155	$ 1,223
State income taxes, net of federal income tax effect	80	118	93
State law changes, net of federal income tax effect	38	0	6
Income Tax Reconciliation Reduction In Unrecognized Tax Benefits	1	(18)	(83)
Tax expense related to equity awards	(13)	(42)	(33)
Change in valuation allowance	(1,221)	(1,418)	(281)
Other, net	16	3	(21)
Income tax (expense) benefit	$ 254	$ 166	$ (1,058)
Effective income tax rate	(9.60%)	(5.00%)	(30.30%)