Debt (Schedule of Debt) (Details) CAD in Millions	Sep. 30, 2015 USD ($)	Sep. 30, 2015 CAD	Jun. 15, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 3,900,000,000			$ 3,900,000,000
Debt	16,609,000,000			15,993,000,000
Corporate Debt
Debt Instrument [Line Items]
Unamortized Net Discount	(3,000,000)			(3,000,000)
Debt	$ 6,318,000,000			6,431,000,000
Senior Term Facility
Debt Instrument [Line Items]
Average interest rate (as a percent)	3.26%	3.26%
Nominal Unpaid Principal Balance	$ 2,067,000,000			2,083,000,000
Senior ABL Facility
Debt Instrument [Line Items]
Average interest rate (as a percent)	2.73%	2.73%
Nominal Unpaid Principal Balance	$ 253,000,000			344,000,000
Promissory Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	7.00%	7.00%
Nominal Unpaid Principal Balance	$ 27,000,000			27,000,000
Other Corporate Debt
Debt Instrument [Line Items]
Average interest rate (as a percent)	3.94%	3.94%
Nominal Unpaid Principal Balance	$ 68,000,000			74,000,000
Fleet Debt
Debt Instrument [Line Items]
Unamortized Net Discount	8,000,000			7,000,000
Debt	10,291,000,000			9,562,000,000
U.S. Fleet Medium Term Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	1,608,000,000			2,258,000,000
U.S. Fleet Medium Term Notes Series 2009-2 Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 0			404,000,000
U.S. Fleet Medium Term Notes Series 2010-1 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	4.26%	4.26%
Nominal Unpaid Principal Balance	$ 428,000,000			490,000,000
U.S. Fleet Medium Term Notes Series 2011-1 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	3.51%	3.51%
Nominal Unpaid Principal Balance	$ 230,000,000			414,000,000
U.S. Fleet Medium Term Notes Series 2013-1 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.68%	1.68%
Nominal Unpaid Principal Balance	$ 950,000,000			950,000,000
RCFC U.S. ABS Program
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	0			433,000,000
RCFC Series 2011-1 Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	0			167,000,000	$ 500,000,000
RCFC Series 2011-2 Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	0			266,000,000	$ 400,000,000
HVF II U.S. ABS Program
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 4,485,000,000			3,844,000,000
HVF II Series 2013-A
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.16%	1.16%
Nominal Unpaid Principal Balance	$ 1,129,000,000			1,999,000,000
HVF II Series 2013-B
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.16%	1.16%
Nominal Unpaid Principal Balance	$ 1,345,000,000			976,000,000
HVF II Series 2014-A
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.70%	1.70%
Nominal Unpaid Principal Balance	$ 2,011,000,000			869,000,000
HVF II Us Fleet Variable Medium Term Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 780,000,000			0
Us Fleet Medium Term Notes 2015 Series 2
Debt Instrument [Line Items]
Average interest rate (as a percent)	2.93%	2.93%
Nominal Unpaid Principal Balance	$ 780,000,000			0
Donlen ABS Program
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 244,000,000			247,000,000
HFLF Series 2013-2 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.22%	1.22%
Nominal Unpaid Principal Balance	$ 244,000,000			247,000,000
HFLF Medium Term Notes
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 946,000,000			900,000,000
HFLF Series 2013-A Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	0.87%	0.87%
Nominal Unpaid Principal Balance	$ 321,000,000			500,000,000
HFLF Series 2014-1 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	0.74%	0.74%
Nominal Unpaid Principal Balance	$ 330,000,000			400,000,000
HFLF Series 2015-1 Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	0.87%	0.87%
Nominal Unpaid Principal Balance	$ 295,000,000		$ 300,000,000	0
Other Fleet Debt
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 2,228,000,000			1,880,000,000
U.S. Fleet Financing Facility
Debt Instrument [Line Items]
Average interest rate (as a percent)	2.95%	2.95%
Nominal Unpaid Principal Balance	$ 190,000,000			164,000,000
European Revolving Credit Facility
Debt Instrument [Line Items]
Average interest rate (as a percent)	2.38%	2.38%
Nominal Unpaid Principal Balance	$ 382,000,000			304,000,000
European Fleet Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	4.375%	4.375%
Nominal Unpaid Principal Balance	$ 478,000,000			517,000,000
European Securitization
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.88%	1.88%
Nominal Unpaid Principal Balance	$ 396,000,000			270,000,000
Canadian Securitization
Debt Instrument [Line Items]
Average interest rate (as a percent)	1.78%	1.78%
Nominal Unpaid Principal Balance	$ 224,000,000	CAD 350		0
Hertz Sponsored Canadian Securitization [Member]
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	0			105,000,000
Dollar Thrifty Sponsored Canadian Securitization
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 0			40,000,000
Australian Securitization
Debt Instrument [Line Items]
Average interest rate (as a percent)	3.68%	3.68%
Nominal Unpaid Principal Balance	$ 87,000,000			112,000,000
Brazilian Fleet Financing
Debt Instrument [Line Items]
Average interest rate (as a percent)	18.04%	18.04%
Nominal Unpaid Principal Balance	$ 7,000,000			11,000,000
Capitalized Leases
Debt Instrument [Line Items]
Average interest rate (as a percent)	3.03%	3.03%
Nominal Unpaid Principal Balance	$ 472,000,000			364,000,000
Senior Notes
Debt Instrument [Line Items]
Average interest rate (as a percent)	6.58%	6.58%
Nominal Unpaid Principal Balance	$ 3,900,000,000			3,900,000,000
4.25% Senior Notes due April 2018
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 250,000,000			250,000,000
Interest rate (as a percentage)	4.25%	4.25%
7.50% Senior Notes due October 2018
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 700,000,000			700,000,000
Interest rate (as a percentage)	7.50%	7.50%
6.75% Senior Notes due April 2019
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 1,250,000,000			1,250,000,000
Interest rate (as a percentage)	6.75%	6.75%
5.875% Senior Notes due October 2020
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 700,000,000			700,000,000
Interest rate (as a percentage)	5.875%	5.875%
7.375% Senior Notes due January 2021
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 500,000,000			500,000,000
Interest rate (as a percentage)	7.375%	7.375%
6.25% Senior Notes due October 2022
Debt Instrument [Line Items]
Nominal Unpaid Principal Balance	$ 500,000,000			$ 500,000,000
Interest rate (as a percentage)	6.25%	6.25%