Derivatives (Narrative) (Details)	12 Months Ended			12 Months Ended			12 Months Ended						12 Months Ended				12 Months Ended
	Dec. 31, 2011 USD ($)	Dec. 31, 2011 Prepaid Expenses And Other Assets [Member] USD ($)	Dec. 31, 2010 Accrued Expenses And Other Liabilities [Member] USD ($)	Dec. 31, 2011 Swap [Member] USD ($) gal	Dec. 31, 2010 Swap [Member] USD ($) gal	Dec. 31, 2011 Swap [Member] Accrued Expenses And Other Liabilities [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Forward [Member] CAD	Dec. 31, 2010 Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2011 Maximum [Member] USD ($)	Dec. 31, 2010 Maximum [Member] USD ($)	Dec. 31, 2010 Maximum [Member] Prepaid Expenses And Other Assets [Member] USD ($)	Dec. 31, 2011 Maximum [Member] Swap [Member] USD ($)	Dec. 31, 2011 Maximum [Member] Swap [Member] Prepaid Expenses And Other Assets [Member] USD ($)	Dec. 31, 2010 Maximum [Member] Swap [Member] Prepaid Expenses And Other Assets [Member] USD ($)	Dec. 31, 2011 Maximum [Member] Swap [Member] Accrued Expenses And Other Liabilities [Member] USD ($)	Dec. 31, 2010 Maximum [Member] Foreign Exchange Forward [Member] USD ($)	Dec. 31, 2011 Cost Of Equipment Rentals Excluding Depreciation [Member] Designated as Hedging Instrument [Member] Swap [Member] USD ($)		Dec. 31, 2010 Cost Of Equipment Rentals Excluding Depreciation [Member] Designated as Hedging Instrument [Member] Swap [Member] USD ($)
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount (in gallons)				4,200,000
Derivative Purchases Of Underlying Currency								221,000,000
Derivative Asset, Fair Value, Gross Asset		0										1,000,000		0	1,000,000
Derivative Liability, Fair Value, Gross Liability			0			1,000,000										1,000,000
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax										1,000,000	1,000,000
Hedging Activities Net Cash Flow Impact				(22,000,000)					(11,000,000)				1,000,000				1,000,000
Derivative Purchases Of Underlying Commodity (in gallons)				5,900,000	3,600,000
Derivative Instruments, Gain Recognized in Income				4,000,000	13,000,000
Gain (Loss) on Hedged Item				(23,000,000)	(11,000,000)		(4,000,000)		(13,000,000)									(23,000,000)	[1],[2]	(11,000,000)	[1],[2]
Derivative Instrument Threshold For Inclusion	$ 1,000,000

[1] Amounts recognized on derivative represent the effective portion of the fixed price diesel swaps.

[2] Amounts recognized on hedged item reflect the use of 5.9 million and 3.6 million gallons of diesel covered by the fixed price swaps during the years ended December 31, 2011 and 2010, respectively.