Guarantor And Non-Guarantor Consolidating Condensed Financial Statements (Consolidating Condensed Statements Of Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Revenues	$ 1,920	$ 1,968
Expenses
Operating	1,071	1,092
Vehicle depreciation and lease charges, net		515
Vehicle depreciation and lease charges, net	485	515
Selling, general and administrative	284	296
Vehicle interest, net	81	72
Non-vehicle related depreciation and amortization	67	61
Interest expense	42	46
Intercompany interest expense (income)	0	0
Early extinguishment of debt	0	5
Restructuring and other related charges	21	6
Transaction-related costs, net	5	4
Total expenses	2,056	2,097
Income (loss) before income taxes and equity in earnings of subsidiaries	(136)	(129)
Provision for (benefit from) income taxes	45	42
Equity in earnings (loss) of subsidiaries	0	0
Net income (loss)	(91)	(87)
Comprehensive income (loss)	96	79
Eliminations [Member]
Revenues
Revenues	(572)	(575)
Expenses
Operating	0	0
Vehicle depreciation and lease charges, net		(525)
Vehicle depreciation and lease charges, net	(508)
Selling, general and administrative	0	0
Vehicle interest, net	(64)	(50)
Non-vehicle related depreciation and amortization	0	0
Interest expense	0	0
Intercompany interest expense (income)	0	0
Early extinguishment of debt	0
Restructuring and other related charges	0	0
Transaction-related costs, net	0	0
Total expenses	(572)	(575)
Income (loss) before income taxes and equity in earnings of subsidiaries	0	0
Provision for (benefit from) income taxes	0	0
Equity in earnings (loss) of subsidiaries	(2)	(84)
Net income (loss)	(2)	(84)
Comprehensive income (loss)	1	94
Parent Company [Member]
Revenues
Revenues	0	0
Expenses
Operating	0	1
Vehicle depreciation and lease charges, net		0
Vehicle depreciation and lease charges, net	0
Selling, general and administrative	11	18
Vehicle interest, net	0	0
Non-vehicle related depreciation and amortization	0	0
Interest expense	0	0
Intercompany interest expense (income)	(3)	(3)
Early extinguishment of debt	0
Restructuring and other related charges	3	0
Transaction-related costs, net	0	0
Total expenses	11	16
Income (loss) before income taxes and equity in earnings of subsidiaries	(11)	(16)
Provision for (benefit from) income taxes	4	6
Equity in earnings (loss) of subsidiaries	(84)	(77)
Net income (loss)	(91)	(87)
Comprehensive income (loss)	96	79
Subsidiaries [Member]
Revenues
Revenues	0	0
Expenses
Operating	0	4
Vehicle depreciation and lease charges, net		0
Vehicle depreciation and lease charges, net	0
Selling, general and administrative	2	3
Vehicle interest, net	0	0
Non-vehicle related depreciation and amortization	0	0
Interest expense	34	39
Intercompany interest expense (income)	(14)	22
Early extinguishment of debt	0	5
Restructuring and other related charges	0	0
Transaction-related costs, net	0	0
Total expenses	22	73
Income (loss) before income taxes and equity in earnings of subsidiaries	(22)	(73)
Provision for (benefit from) income taxes	8	19
Equity in earnings (loss) of subsidiaries	(70)	(23)
Net income (loss)	(84)	(77)
Comprehensive income (loss)	89	69
Guarantor Subsidiaries [Member]
Revenues
Revenues	1,188	1,184
Expenses
Operating	614	621
Vehicle depreciation and lease charges, net		536
Vehicle depreciation and lease charges, net	529
Selling, general and administrative	163	155
Vehicle interest, net	63	52
Non-vehicle related depreciation and amortization	38	36
Interest expense	0	1
Intercompany interest expense (income)	7	6
Early extinguishment of debt	0
Restructuring and other related charges	14	3
Transaction-related costs, net	1	0
Total expenses	1,429	1,410
Income (loss) before income taxes and equity in earnings of subsidiaries	(241)	(226)
Provision for (benefit from) income taxes	15	19
Equity in earnings (loss) of subsidiaries	156	184
Net income (loss)	(70)	(23)
Comprehensive income (loss)	68	21
Non-Guarantor Subsidiaries [Member]
Revenues
Revenues	1,304	1,359
Expenses
Operating	457	466
Vehicle depreciation and lease charges, net		504
Vehicle depreciation and lease charges, net	464
Selling, general and administrative	108	120
Vehicle interest, net	82	70
Non-vehicle related depreciation and amortization	29	25
Interest expense	8	6
Intercompany interest expense (income)	10	(25)
Early extinguishment of debt	0
Restructuring and other related charges	4	3
Transaction-related costs, net	4	4
Total expenses	1,166	1,173
Income (loss) before income taxes and equity in earnings of subsidiaries	138	186
Provision for (benefit from) income taxes	18	(2)
Equity in earnings (loss) of subsidiaries	0	0
Net income (loss)	156	184
Comprehensive income (loss)	$ (158)	$ (184)