CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Total revenues	$ 2,306	$ 2,116	$ 1,891	$ 1,734	$ 1,922	$ 1,766	$ 1,597	$ 1,356	$ 8,047	$ 6,641	$ 5,762
Cost of revenues:
Cost of equipment rentals, excluding depreciation									2,614	2,151	1,862
Depreciation of rental equipment									1,363	1,124	990
Total cost of revenues									4,683	3,872	3,359
Gross profit	998	938	782	646	827	773	655	514	3,364	2,769	2,403
Selling, general and administrative expenses									1,038	903	719
Merger related costs	22				18				36	50	0
Restructuring charge	16				22				31	50	14
Non-rental depreciation and amortization									308	259	255
Operating income	563	578	470	340	462	448	340	257	1,951	1,507	1,415
Interest expense, net									481	464	511
Other income, net									(6)	(5)	(5)
Income before provision (benefit) for income taxes									1,476	1,048	909
Provision (benefit) for income taxes (note 13)									380	(298)	343
Net income	$ 310	$ 333	$ 270	$ 183	$ 897	$ 199	$ 141	$ 109	$ 1,096	$ 1,346	$ 566
Basic earnings per share (in dollars per share)	$ 3.84	$ 4.05	$ 3.22	$ 2.18	$ 10.60	$ 2.36	$ 1.67	$ 1.29	$ 13.26	$ 15.91	$ 6.49
Diluted earnings per share (in dollars per share)	$ 3.80	$ 4.01	$ 3.20	$ 2.15	$ 10.45	$ 2.33	$ 1.65	$ 1.27	$ 13.12	$ 15.73	$ 6.45
Total equipment rentals
Revenues:
Total revenues									$ 6,940	$ 5,715	$ 4,941
Sales of rental equipment
Revenues:
Revenue from contract with customer, excluding assessed tax									664	550	496
Cost of revenues:
Cost of goods and services sold									386	330	292
Sales of new equipment
Revenues:
Revenue from contract with customer, excluding assessed tax									208	178	144
Cost of revenues:
Cost of goods and services sold									179	152	119
Contractor supplies sales
Revenues:
Revenue from contract with customer, excluding assessed tax									91	80	79
Cost of revenues:
Cost of goods and services sold									60	56	55
Service and other revenues
Revenues:
Revenue from contract with customer, excluding assessed tax									144	118	102
Cost of revenues:
Cost of goods and services sold									$ 81	$ 59	$ 41