Consolidating Condensed Statements of Operations (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	$ 6,026,000,000	$ 6,026,000,000	$ 5,707,000,000
Other	2,476,000,000	2,459,000,000	2,230,000,000
Net revenues	8,502,000,000	8,485,000,000	7,937,000,000
Operating	4,284,000,000	4,251,000,000	4,074,000,000
Vehicle depreciation and lease charges, net	1,933,000,000	1,996,000,000	1,811,000,000
Selling, general and administrative	1,093,000,000	1,080,000,000	1,019,000,000
Vehicle interest, net	289,000,000	282,000,000	264,000,000
Non-vehicle related depreciation and amortization	218,000,000	180,000,000	152,000,000
Interest expense	194,000,000	209,000,000	228,000,000
Intercompany interest expense (income)	0	0	0
Early extinguishment of debt	23,000,000	56,000,000	147,000,000
Restructuring expense	18,000,000	26,000,000	61,000,000
Transaction-related costs, net	68,000,000	13,000,000	51,000,000
Impairment	0	0	33,000,000
Total expenses	8,120,000,000	8,093,000,000	7,840,000,000
Income before income taxes	382,000,000	392,000,000	97,000,000
Provision for (benefit from) income taxes	69,000,000	147,000,000	81,000,000
Equity in earnings (loss) of subsidiaries	0	0	0
Net income	313,000,000	245,000,000	16,000,000
Total comprehensive income	188,000,000	106,000,000	23,000,000
Parent Company
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	0	0	0
Other	0	0	0
Net revenues	0	0	0
Operating	2,000,000	10,000,000	7,000,000
Vehicle depreciation and lease charges, net	0	0	0
Selling, general and administrative	32,000,000	27,000,000	35,000,000
Vehicle interest, net	0	0	0
Non-vehicle related depreciation and amortization	0	0	0
Interest expense	0	2,000,000	3,000,000
Intercompany interest expense (income)	(12,000,000)	(13,000,000)	(12,000,000)
Early extinguishment of debt	0	0	53,000,000
Restructuring expense	0	0	0
Transaction-related costs, net	0	1,000,000	1,000,000
Impairment			0
Total expenses	22,000,000	27,000,000	87,000,000
Income before income taxes	(22,000,000)	(27,000,000)	(87,000,000)
Provision for (benefit from) income taxes	(9,000,000)	(10,000,000)	(14,000,000)
Equity in earnings (loss) of subsidiaries	326,000,000	262,000,000	89,000,000
Net income	313,000,000	245,000,000	16,000,000
Total comprehensive income	188,000,000	106,000,000	23,000,000
Subsidiary Issuers
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	0	0	0
Other	0	0	0
Net revenues	0	0	0
Operating	17,000,000	13,000,000	15,000,000
Vehicle depreciation and lease charges, net	1,000,000	1,000,000	0
Selling, general and administrative	15,000,000	23,000,000	6,000,000
Vehicle interest, net	0	0	0
Non-vehicle related depreciation and amortization	1,000,000	2,000,000	2,000,000
Interest expense	159,000,000	163,000,000	196,000,000
Intercompany interest expense (income)	(11,000,000)	(11,000,000)	(30,000,000)
Early extinguishment of debt	23,000,000	56,000,000	94,000,000
Restructuring expense	0	0	0
Transaction-related costs, net	22,000,000	8,000,000	24,000,000
Impairment			33,000,000
Total expenses	227,000,000	255,000,000	340,000,000
Income before income taxes	(227,000,000)	(255,000,000)	(340,000,000)
Provision for (benefit from) income taxes	(178,000,000)	(108,000,000)	(124,000,000)
Equity in earnings (loss) of subsidiaries	375,000,000	409,000,000	305,000,000
Net income	326,000,000	262,000,000	89,000,000
Total comprehensive income	203,000,000	123,000,000	96,000,000
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	4,124,000,000	4,038,000,000	3,786,000,000
Other	1,181,000,000	1,167,000,000	1,098,000,000
Net revenues	5,305,000,000	5,205,000,000	4,884,000,000
Operating	2,587,000,000	2,525,000,000	2,425,000,000
Vehicle depreciation and lease charges, net	1,819,000,000	1,920,000,000	1,776,000,000
Selling, general and administrative	619,000,000	602,000,000	591,000,000
Vehicle interest, net	204,000,000	200,000,000	182,000,000
Non-vehicle related depreciation and amortization	133,000,000	111,000,000	97,000,000
Interest expense	(5,000,000)	2,000,000	0
Intercompany interest expense (income)	16,000,000	1,000,000	6,000,000
Early extinguishment of debt	0	0	0
Restructuring expense	6,000,000	7,000,000	25,000,000
Transaction-related costs, net	6,000,000	(20,000,000)	3,000,000
Impairment			0
Total expenses	5,385,000,000	5,348,000,000	5,105,000,000
Income before income taxes	(80,000,000)	(143,000,000)	(221,000,000)
Provision for (benefit from) income taxes	170,000,000	186,000,000	156,000,000
Equity in earnings (loss) of subsidiaries	625,000,000	738,000,000	682,000,000
Net income	375,000,000	409,000,000	305,000,000
Total comprehensive income	253,000,000	273,000,000	310,000,000
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	1,902,000,000	1,988,000,000	1,921,000,000
Other	3,335,000,000	3,426,000,000	3,086,000,000
Net revenues	5,237,000,000	5,414,000,000	5,007,000,000
Operating	1,678,000,000	1,703,000,000	1,627,000,000
Vehicle depreciation and lease charges, net	1,936,000,000	1,996,000,000	1,806,000,000
Selling, general and administrative	427,000,000	428,000,000	387,000,000
Vehicle interest, net	302,000,000	295,000,000	265,000,000
Non-vehicle related depreciation and amortization	84,000,000	67,000,000	53,000,000
Interest expense	40,000,000	42,000,000	29,000,000
Intercompany interest expense (income)	7,000,000	23,000,000	36,000,000
Early extinguishment of debt	0	0	0
Restructuring expense	12,000,000	19,000,000	36,000,000
Transaction-related costs, net	40,000,000	24,000,000	23,000,000
Impairment			0
Total expenses	4,526,000,000	4,597,000,000	4,262,000,000
Income before income taxes	711,000,000	817,000,000	745,000,000
Provision for (benefit from) income taxes	86,000,000	79,000,000	63,000,000
Equity in earnings (loss) of subsidiaries	0	0	0
Net income	625,000,000	738,000,000	682,000,000
Total comprehensive income	504,000,000	624,000,000	657,000,000
Eliminations
Condensed Financial Statements, Captions [Line Items]
Vehicle rental	0	0	0
Other	(2,040,000,000)	(2,134,000,000)	(1,954,000,000)
Net revenues	(2,040,000,000)	(2,134,000,000)	(1,954,000,000)
Operating	0	0	0
Vehicle depreciation and lease charges, net	(1,823,000,000)	(1,921,000,000)	(1,771,000,000)
Selling, general and administrative	0	0	0
Vehicle interest, net	(217,000,000)	(213,000,000)	(183,000,000)
Non-vehicle related depreciation and amortization	0	0	0
Interest expense	0	0	0
Intercompany interest expense (income)	0	0	0
Early extinguishment of debt	0	0	0
Restructuring expense	0	0	0
Transaction-related costs, net	0	0	0
Impairment			0
Total expenses	(2,040,000,000)	(2,134,000,000)	(1,954,000,000)
Income before income taxes	0	0	0
Provision for (benefit from) income taxes	0	0	0
Equity in earnings (loss) of subsidiaries	(1,326,000,000)	(1,409,000,000)	(1,076,000,000)
Net income	(1,326,000,000)	(1,409,000,000)	(1,076,000,000)
Total comprehensive income	$ (960,000,000)	$ (1,020,000,000)	$ (1,063,000,000)