Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING STATEMENTS OF INCOME (Details) - 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:
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 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 (income) expense, net										648	481	464
Other (income) expense, net										(10)	(6)	(5)
Income before provision (benefit) for income taxes										1,514	1,476	1,048
Provision for income taxes										340	380	(298)
Income before equity in net earnings (loss) of subsidiaries										1,174	1,096	1,346
Equity in net earnings (loss) of subsidiaries										0	0	0
Net income		$ 338	$ 391	$ 270	$ 175	$ 310	$ 333	$ 270	$ 183	1,174	1,096	1,346
Other comprehensive income (loss)	[1]									51	(86)	67
Comprehensive income										1,225	1,010	1,413
Eliminations
Revenues:
Revenues										0	0	0
Cost of equipment rentals, excluding depreciation										0	0	0
Depreciation of rental equipment										0	0	0
Total cost of revenues										0	0	0
Gross profit										0	0	0
Selling, general and administrative expenses										0	0	0
Merger related costs										0	0	0
Restructuring charge										0	0	0
Non-rental depreciation and amortization										0	0	0
Operating income										0	0	0
Interest (income) expense, net										0	(1)	(5)
Other (income) expense, net										0	0	0
Income before provision (benefit) for income taxes										0	1	5
Provision for income taxes										0	0	0
Income before equity in net earnings (loss) of subsidiaries										0	1	5
Equity in net earnings (loss) of subsidiaries										(788)	(751)	(1,162)
Net income										(788)	(750)	(1,157)
Other comprehensive income (loss)										(149)	273	(189)
Comprehensive income										(937)	(477)	(1,346)
Parent
Revenues:
Merger related costs											0
Parent | Reportable Legal Entities
Revenues:
Revenues										0	0	0
Cost of equipment rentals, excluding depreciation										0	0	0
Depreciation of rental equipment										0	0	0
Total cost of revenues										0	0	0
Gross profit										0	0	0
Selling, general and administrative expenses										92	25	103
Merger related costs										0		0
Restructuring charge										0	0	0
Non-rental depreciation and amortization										19	17	15
Operating income										(111)	(42)	(118)
Interest (income) expense, net										(68)	(39)	(15)
Other (income) expense, net										(763)	(657)	(543)
Income before provision (benefit) for income taxes										720	654	440
Provision for income taxes										167	164	144
Income before equity in net earnings (loss) of subsidiaries										553	490	296
Equity in net earnings (loss) of subsidiaries										621	606	1,050
Net income										1,174	1,096	1,346
Other comprehensive income (loss)										51	(86)	67
Comprehensive income										1,225	1,010	1,413
URNA | Reportable Legal Entities
Revenues:
Revenues										8,533	7,387	6,076
Cost of equipment rentals, excluding depreciation										2,807	2,370	1,933
Depreciation of rental equipment										1,490	1,258	1,033
Total cost of revenues										5,136	4,268	3,502
Gross profit										3,397	3,119	2,574
Selling, general and administrative expenses										840	860	682
Merger related costs										1	36	50
Restructuring charge										19	29	49
Non-rental depreciation and amortization										354	266	223
Operating income										2,183	1,928	1,570
Interest (income) expense, net										686	497	469
Other (income) expense, net										866	742	596
Income before provision (benefit) for income taxes										631	689	505
Provision for income taxes										139	181	(469)
Income before equity in net earnings (loss) of subsidiaries										492	508	974
Equity in net earnings (loss) of subsidiaries										129	98	76
Net income										621	606	1,050
Other comprehensive income (loss)										51	(86)	67
Comprehensive income										672	520	1,117
Guarantor Subsidiaries
Revenues:
Merger related costs											0
Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenues										0	0	0
Cost of equipment rentals, excluding depreciation										0	0	0
Depreciation of rental equipment										0	0	0
Total cost of revenues										0	0	0
Gross profit										0	0	0
Selling, general and administrative expenses										0	0	0
Merger related costs										0		0
Restructuring charge										0	0	0
Non-rental depreciation and amortization										0	0	0
Operating income										0	0	0
Interest (income) expense, net										0	0	3
Other (income) expense, net										0	0	0
Income before provision (benefit) for income taxes										0	0	(3)
Provision for income taxes										0	0	0
Income before equity in net earnings (loss) of subsidiaries										0	0	(3)
Equity in net earnings (loss) of subsidiaries										38	47	36
Net income										38	47	33
Other comprehensive income (loss)										50	(82)	67
Comprehensive income										88	(35)	100
Foreign | Reportable Legal Entities
Revenues:
Revenues										817	660	565
Cost of equipment rentals, excluding depreciation										319	244	218
Depreciation of rental equipment										141	105	91
Total cost of revenues										545	415	370
Gross profit										272	245	195
Selling, general and administrative expenses										116	96	80
Merger related costs										0	0	0
Restructuring charge										(1)	2	1
Non-rental depreciation and amortization										34	25	21
Operating income										123	122	93
Interest (income) expense, net										0	0	0
Other (income) expense, net										61	51	45
Income before provision (benefit) for income taxes										62	71	48
Provision for income taxes										9	20	12
Income before equity in net earnings (loss) of subsidiaries										53	51	36
Equity in net earnings (loss) of subsidiaries										0	0	0
Net income										53	51	36
Other comprehensive income (loss)										48	(105)	55
Comprehensive income										101	(54)	91
SPV | Reportable Legal Entities
Revenues:
Revenues										1	0	0
Cost of equipment rentals, excluding depreciation										0	0	0
Depreciation of rental equipment										0	0	0
Total cost of revenues										0	0	0
Gross profit										1	0	0
Selling, general and administrative expenses										44	57	38
Merger related costs										0	0	0
Restructuring charge										0	0	0
Non-rental depreciation and amortization										0	0	0
Operating income										(43)	(57)	(38)
Interest (income) expense, net										30	24	12
Other (income) expense, net										(174)	(142)	(103)
Income before provision (benefit) for income taxes										101	61	53
Provision for income taxes										25	15	15
Income before equity in net earnings (loss) of subsidiaries										76	46	38
Equity in net earnings (loss) of subsidiaries										0	0	0
Net income										76	46	38
Other comprehensive income (loss)										0	0	0
Comprehensive income										76	46	38
Total equipment rentals
Revenues:
Revenue from contract with customer, excluding assessed tax										7,964	6,940	5,715
Revenues										7,964	6,940	5,715
Total equipment rentals | Eliminations
Revenues:
Revenues										0	0	0
Total equipment rentals | Parent | Reportable Legal Entities
Revenues:
Revenues										0	0	0
Total equipment rentals | URNA | Reportable Legal Entities
Revenues:
Revenues										7,282	6,388	5,253
Total equipment rentals | Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenues										0	0	0
Total equipment rentals | Foreign | Reportable Legal Entities
Revenues:
Revenues										681	552	462
Total equipment rentals | SPV | Reportable Legal Entities
Revenues:
Revenues										1	0	0
Sales of rental equipment
Revenues:
Revenue from contract with customer, excluding assessed tax										831	664	550
Cost of goods and services sold										518	386	330
Sales of rental equipment | Eliminations
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of rental equipment | Parent | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of rental equipment | URNA | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										757	609	494
Cost of goods and services sold										477	358	302
Sales of rental equipment | Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of rental equipment | Foreign | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										74	55	56
Cost of goods and services sold										41	28	28
Sales of rental equipment | SPV | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of new equipment
Revenues:
Revenue from contract with customer, excluding assessed tax										268	208	178
Cost of goods and services sold										231	179	152
Sales of new equipment | Eliminations
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of new equipment | Parent | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of new equipment | URNA | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										238	184	157
Cost of goods and services sold										205	159	134
Sales of new equipment | Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Sales of new equipment | Foreign | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										30	24	21
Cost of goods and services sold										26	20	18
Sales of new equipment | SPV | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Contractor supplies sales
Revenues:
Revenue from contract with customer, excluding assessed tax										104	91	80
Cost of goods and services sold										73	60	56
Contractor supplies sales | Eliminations
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Contractor supplies sales | Parent | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Contractor supplies sales | URNA | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										92	80	70
Cost of goods and services sold										65	52	49
Contractor supplies sales | Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Contractor supplies sales | Foreign | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										12	11	10
Cost of goods and services sold										8	8	7
Contractor supplies sales | SPV | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Service and other revenues
Revenues:
Revenue from contract with customer, excluding assessed tax										184	144	118
Cost of goods and services sold										102	81	59
Service and other revenues | Eliminations
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Service and other revenues | Parent | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Service and other revenues | URNA | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										164	126	102
Cost of goods and services sold										92	71	51
Service and other revenues | Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										0	0	0
Service and other revenues | Foreign | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										20	18	16
Cost of goods and services sold										10	10	8
Service and other revenues | SPV | Reportable Legal Entities
Revenues:
Revenue from contract with customer, excluding assessed tax										0	0	0
Cost of goods and services sold										$ 0	$ 0	$ 0

[1] There were no material reclassifications from accumulated other comprehensive loss reflected in other comprehensive income (loss) during the years ended December 31, 2019, 2018 or 2017. There is no tax impact related to the foreign currency translation adjustments, as the earnings are considered permanently reinvested (see note 14 to the consolidated financial statements for further discussion addressing this determination). There were no material taxes associated with other comprehensive income (loss) during the years ended December 31, 2019, 2018 or 2017.