Quarterly Financial Information (Unaudited) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2011 branches	Dec. 31, 2010 branches employees	Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009
Selected Quarterly Financial Information [Abstract]
RSC merger related costs			$ 19	$ 0		$ 0
Restructuring, Number of Locations Eliminated	18	22
Restructuring Charges		15	19	34		31
Asset Impairment Charges		6
Gains (Losses) on Extinguishment of Debt		25	3	28	[1]	(7)
Write off of Deferred Debt Issuance Cost				12
Self Insurance Reserve Benefit	8	24
Extinguishment of Debt, Amount		814	5	1,273
Repayments of Debt and Capital Lease Obligations			1,813	3,606		3,658
Repayments of Long-term Debt		827
Write Off Previously Terminated Derivative Transaction		4		4
Restructuring and Related Cost, Number of Positions Eliminated		100
Tax Adjustments, Settlements, and Unusual Provisions		7	(3)	7
RSC [Member]
Selected Quarterly Financial Information [Abstract]
RSC merger related costs	19
Non Rental Depreciation And Amortization [Member]
Selected Quarterly Financial Information [Abstract]
Asset Impairment Charges	3
Cost Of Equipment Rentals Excluding Depreciation [Member]
Selected Quarterly Financial Information [Abstract]
Self Insurance Reserve Benefit		18
Discontinued Operation or Asset Disposal [Member]
Selected Quarterly Financial Information [Abstract]
Self Insurance Reserve Benefit		6
QUIPS [Member] | Unconsolidated Subsidiaries [Member]
Selected Quarterly Financial Information [Abstract]
Extinguishment of Debt, Amount	32		69	22
Repayments of Debt and Capital Lease Obligations	32		68	9
Six Point Five Percent Subordinated Convertible Debentures [Member]
Selected Quarterly Financial Information [Abstract]
Gains (Losses) on Extinguishment of Debt	(1)		2	(13)
Extinguishment of Debt, Amount			69	22
Debt Instrument, Interest Rate, Stated Percentage	6.50%		6.50%
7 3/4 percent Senior Subordinated Notes
Selected Quarterly Financial Information [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.75%		7.75%
7 percent Senior Subordinated Notes
Selected Quarterly Financial Information [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.00%		7.00%
1 7/8 percent Convertible Senior Subordinated Notes
Selected Quarterly Financial Information [Abstract]
Extinguishment of Debt, Amount			93
Debt Instrument, Interest Rate, Stated Percentage	1.875%		1.875%
Facility Closing [Member]
Selected Quarterly Financial Information [Abstract]
Restructuring Charges	$ 14

[1] The amount of the loss is calculated as the difference between the net carrying amount of the related security and the repurchase price. The net carrying amounts of the securities are less than the principal amounts due to capitalized debt issuance costs and any original issue discount. Aggregate costs of less than $1 and $16 were written off in the years ended December 31, 2011 and 2010, respectively, in connection with the repurchases/redemptions. The $16 of aggregate costs written off in the year ended December 31, 2010 was comprised of $12 of write-offs of debt issuance costs and a $4 write-off of a previously terminated derivative transaction. The losses are reflected in interest expense, net in our consolidated statements of income.