Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended															9 Months Ended		12 Months Ended	1 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended						3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 U.S. Fleet Variable Funding Notes	Dec. 31, 2011 U.S. Fleet Variable Funding Notes	Sep. 30, 2012 Australian Securitization		Dec. 31, 2011 Australian Securitization		Sep. 30, 2012 U.S. Fleet Variable Funding Notes Series 2009-1		May 31, 2012 U.S. Fleet Variable Funding Notes Series 2009-1	Mar. 31, 2012 U.S. Fleet Variable Funding Notes Series 2009-1	Dec. 31, 2011 U.S. Fleet Variable Funding Notes Series 2009-1		Sep. 30, 2012 Unleaded gasoline swaps gallon	Sep. 30, 2012 Diesel swaps gallon	Sep. 30, 2012 Interest rate caps	Sep. 30, 2012 Interest rate caps Donlen Corporation	Dec. 31, 2011 Interest rate caps U.S. Fleet Variable Funding Notes	Dec. 31, 2010 Interest rate caps Australian Securitization	Sep. 30, 2012 Foreign exchange forward contracts	Sep. 30, 2012 Foreign exchange options	Dec. 31, 2011 Foreign exchange options	Sep. 30, 2012 Level 1	Sep. 30, 2011 Level 1	Sep. 30, 2012 Level 1	Sep. 30, 2011 Level 1	Dec. 31, 2011 Level 1	Dec. 31, 2010 Level 1	Sep. 30, 2012 Level 2	Dec. 31, 2011 Level 2	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Gasoline swaps	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Gasoline swaps	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Gasoline swaps	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Gasoline swaps	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments Gasoline swaps	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Interest rate caps	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Interest rate caps	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Interest rate caps	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Interest rate caps	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments Interest rate caps	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Foreign exchange forward contracts	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange forward contracts	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Foreign exchange forward contracts	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange forward contracts	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange forward contracts	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Interest rate swaps	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments Interest rate swaps	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Foreign exchange options	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange options	Sep. 30, 2012 Recurring Derivatives not designated as hedging instruments Foreign exchange options	Sep. 30, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange options	Dec. 31, 2011 Recurring Derivatives not designated as hedging instruments Foreign exchange options	Sep. 30, 2012 Recurring Level 2	Dec. 31, 2011 Recurring Level 2
Cash and Cash Equivalents and Restricted Cash and Cash Equivalents
Money market accounts included in cash and cash equivalents at fair value																							$ 65.4		$ 65.4		$ 566.0
Money market accounts included in restricted cash and cash equivalents at fair value																							300.4		300.4		142.9
Marketable Securities
Available-for-sale marketable equity securities included in prepaid expenses and other assets at fair value																							41.1		41.1			33.2
Unrealized gains and losses on marketable equity securities net of income taxes included in accumulated other comprehensive income																							2.8	8.2	7.9	6.3
Debt
Maximum initial maturity period of borrowings	93 days
Aggregate fair value of all debt																													12,623.8	11,092.4
Aggregate carrying value of all debt		2,100.0	1,345.0	162.3	[1],[2]	169.3	[1],[2]	1,900.0	[2],[3]			1,000.0	[2],[3]																																													12,296.9	10,925.6
Fair Value of Derivative Instruments
Asset Derivatives																															4.6		4.6		5.0	0.3		0.3		0	0		0		0.5	4.2		4.2		4.4	0	0	0.1		0.1		0.1
Liability Derivatives																															3.3		3.3		2.9	0		0		0.4	0		0		0.4	3.3		3.3		1.9	0	0.2	0		0		0
Amount of Gain or (Loss) Recognized in Income on Derivatives																															(4.1)	9.4	(11.2)	4.4		2.1	(1.9)	0.6	1.0		0	0.1	(0.1)	0.1		(6.2)	11.3	(11.8)	3.4				0	(0.1)	0.1	(0.1)
Derivative purchased, amount																		6.7	0.5
Combined maximum principal amount																		2,100	250
Strike rate (as a percent)																		5.00%	7.00%
Derivative sold, amount																		6.2	0.4
Increase in the credit agreement's borrowing capacity										250	250
Variable rate used to calculate fair values of all interest rate caps																1-month LIBOR yield curve	1-month LIBOR yield curve
Total notional amount																				986.9	45.0	9.1
Outstanding commodity instruments (in gallons)														7,800,000	1,500,000
Premiums paid for options outstanding																					$ 0.2
Maturity period																				4 months

[1] In October 2012, extended to 12/2014. See Note 17—Subsequent Events.

[2] Maturity reference is to the "expected final maturity date" as opposed to the subsequent "legal maturity date." The expected final maturity date is the date by which Hertz and investors in the relevant indebtedness expect the relevant indebtedness to be repaid. The legal final maturity date is the date on which the relevant indebtedness is legally due and payable.

[3] In October 2012, extended to 3/2014. See Note 17—Subsequent Events.