Acquisitions (Details Textuals) (USD $)	3 Months Ended		6 Months Ended				6 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Hill Hire [Member]	Jun. 08, 2011 Hill Hire [Member] Customers Trailer Vehicle Lease	Jun. 30, 2012 Other Acquisitions [Member]	Jun. 30, 2011 Other Acquisitions [Member]	Dec. 31, 2011 Other Acquisitions [Member]	Jun. 30, 2012 Other Acquisitions Completed in Prior Years [Member]	Jun. 30, 2011 Other Acquisitions Completed in Prior Years [Member]
Business Acquisition [Line Items]
Restructuring and other charges (recoveries), net	$ 7,142,000	$ 0	$ 8,007,000	$ 768,000	$ 865,000
Acquisitions (Textuals) [Abstract]
Purchase Price						251,500,000			113,800,000
Number of full service lease vehicles						8,000
Number of rental vehicles						5,700
Number of contractual customers acquired						400
Number of trailers included in fleet						9,700
Purchase Price Adjustment					1,800,000
Payments to Acquire Businesses	400,000	264,800,000	2,426,000	348,584,000			1,500,000	92,900,000		900,000	4,200,000
Goodwill							28,400,000
Customer relationship intangibles							$ 11,900,000