Goodwill and Other Intangible Assets (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Goodwill
Balance at the beginning of the period	$ 2,062,900,000		$ 1,113,100,000
Accumulated impairment losses at the beginning of the period	(721,000,000)		(721,000,000)
Net goodwill, balance at the beginning of the period	1,341,872,000		392,100,000
Goodwill acquired during the period	0		966,900,000
Adjustments to previously recorded purchase price allocation	13,800,000	[1]	(15,300,000)	[2]
Other changes during the period	(3,000,000)	[3]	(1,800,000)	[4]
Total changes in goodwill	10,800,000		949,800,000
Balance at the end of the period	2,073,700,000		2,062,900,000
Accumulated impairment losses at the end of the period	(721,000,000)		(721,000,000)
Net goodwill, balance at the end of the period	1,352,694,000		1,341,872,000
Car Rental
Goodwill
Balance at the beginning of the period	1,287,500,000		419,300,000
Accumulated impairment losses at the beginning of the period	(46,100,000)		(46,100,000)
Net goodwill, balance at the beginning of the period	1,241,400,000		373,200,000
Goodwill acquired during the period	0		884,900,000
Adjustments to previously recorded purchase price allocation	9,200,000	[1]	(15,300,000)	[2]
Other changes during the period	(2,900,000)	[3]	(1,400,000)	[4]
Total changes in goodwill	6,300,000		868,200,000
Balance at the end of the period	1,293,800,000		1,287,500,000
Accumulated impairment losses at the end of the period	(46,100,000)		(46,100,000)
Net goodwill, balance at the end of the period	1,247,700,000		1,241,400,000
Equipment Rental
Goodwill
Balance at the beginning of the period	775,400,000		693,800,000
Accumulated impairment losses at the beginning of the period	(674,900,000)		(674,900,000)
Net goodwill, balance at the beginning of the period	100,500,000		18,900,000
Goodwill acquired during the period	0		82,000,000
Adjustments to previously recorded purchase price allocation	4,600,000	[1]	0	[2]
Other changes during the period	(100,000)	[3]	(400,000)	[4]
Total changes in goodwill	4,500,000		81,600,000
Balance at the end of the period	779,900,000		775,400,000
Accumulated impairment losses at the end of the period	(674,900,000)		(674,900,000)
Net goodwill, balance at the end of the period	$ 105,000,000		$ 100,500,000

[1] Consists of adjustments related to purchase accounting and deferred tax during 2013.

[2] Consists of deferred tax adjustments recorded during 2012.

[3] Primarily consists of changes resulting from the translation of foreign currencies at different exchange rates from the beginning of the period to the end of the period.

[4] Primarily consists of changes resulting from disposals and the translation of foreign currencies at different exchange rates from the beginning of the year to the end of the year.