Consolidated Statements Of Operations - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Vehicle rental									$ 6,219	$ 6,081	$ 6,026
Other									2,629	2,578	2,476
Net revenues									8,848	8,659	8,502
Expenses
Operating									4,472	4,382	4,284
Vehicle depreciation and lease charges, net									2,221	2,047	1,933
Selling, general and administrative									1,120	1,134	1,093
Vehicle interest, net									286	284	289
Non-vehicle related depreciation and amortization									259	253	218
Interest expense related to corporate debt, net:
Interest expense									188	203	194
Early extinguishment of debt									3	27	23
Restructuring and other related charges									63	29	18
Impairment									23	21	68
Asset Impairment Charges									2	0	0
Total expenses									8,637	8,380	8,120
Income before income taxes									211	279	382
Provision for (benefit from) income taxes									(150)	116	69
Net income									$ 361	$ 163	$ 313
Earnings per share
Basic	$ 2.70	$ 2.96	$ 0.04	$ (1.25)	$ (0.35)	$ 2.32	$ 0.39	$ (0.53)	$ 4.32	$ 1.78	$ 3.02
Diluted	$ 2.65	$ 2.91	$ 0.04	$ (1.25)	$ (0.35)	$ 2.28	$ 0.38	$ (0.53)	$ 4.25	$ 1.75	$ 2.98