Income Taxes (Components of income tax expense and reconciliation of effective tax rate) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Current
Federal		$ 0		$ 0		$ (55)
Foreign		22		16		5
State and local		2		1		(1)
Current income tax expense		24		17		(51)
Deferred
Federal		36		(48)		13
Foreign		1		(1)		2
State and local		2		(9)		(11)
Deferred income tax expense (benefit)		39		(58)		4
Total		63		(41)		(47)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate		35.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed tax at statutory tax rate		57		(22)		(38)
State income taxes, net of federal tax benefit		3		(8)		(7)
Non-deductible expenses and other		12	[1]	(6)	[1]	(1)
Foreign taxes		(9)		(5)		(1)
Tax Adjustments, Settlements, and Unusual Provisions	(7)	3		(7)
RSC [Member]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income Tax Reconciliation, Nondeductible Expense, Business Acquisition		$ 6

[1] 2011 non-deductible expenses and other includes $6 due to the non-deductibility of certain costs associated with the proposed RSC acquisition and $3 related to an adjustment of federal and state deferred tax liabilities. 2010 non-deductible expenses and other includes a benefit of $7 related to a correction of a deferred tax asset recognized in prior periods.