CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 2,456	$ 2,488	$ 2,290	$ 2,117	$ 2,306	$ 2,116	$ 1,891	$ 1,734	$ 9,351	$ 8,047	$ 6,641
Cost of revenues:
Cost of equipment rentals, excluding depreciation									3,126	2,614	2,151
Depreciation of rental equipment									1,631	1,363	1,124
Total cost of revenues									5,681	4,683	3,872
Gross profit	965	1,033	911	761	998	938	782	646	3,670	3,364	2,769
Selling, general and administrative expenses									1,092	1,038	903
Merger related costs					22				1	36	50
Restructuring charge					16				18	31	50
Non-rental depreciation and amortization									407	308	259
Operating income	599	656	529	368	563	578	470	340	2,152	1,951	1,507
Interest expense, net									648	481	464
Other income, net									(10)	(6)	(5)
Income before provision (benefit) for income taxes									1,514	1,476	1,048
Provision (benefit) for income taxes (note 14)									340	380	(298)
Net income	$ 338	$ 391	$ 270	$ 175	$ 310	$ 333	$ 270	$ 183	$ 1,174	$ 1,096	$ 1,346
Basic earnings per share (in dollars per share)	$ 4.51	$ 5.10	$ 3.45	$ 2.21	$ 3.84	$ 4.05	$ 3.22	$ 2.18	$ 15.18	$ 13.26	$ 15.91
Diluted earnings per share (in dollars per share)	$ 4.49	$ 5.08	$ 3.44	$ 2.19	$ 3.80	$ 4.01	$ 3.20	$ 2.15	$ 15.11	$ 13.12	$ 15.73
Equipment rentals
Revenues:
Revenues									$ 7,964	$ 6,940	$ 5,715
Total revenues									7,964	6,940	5,715
Sales of rental equipment
Revenues:
Revenues									831	664	550
Cost of revenues:
Cost of goods and services sold									518	386	330
Sales of new equipment
Revenues:
Revenues									268	208	178
Cost of revenues:
Cost of goods and services sold									231	179	152
Contractor supplies sales
Revenues:
Revenues									104	91	80
Cost of revenues:
Cost of goods and services sold									73	60	56
Service and other revenues
Revenues:
Revenues									184	144	118
Cost of revenues:
Cost of goods and services sold									$ 102	$ 81	$ 59