Segment Information (Geographic Area Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									$ 2,256	$ 1,994	$ 2,063
Revenues	$ 2,776	$ 2,596	$ 2,287	$ 2,057	$ 2,279	$ 2,187	$ 1,939	$ 2,125	9,716	8,530	9,351
Goodwill and other intangible assets, net	6,143				5,816				6,143	5,816
Property and equipment, net
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	612				604				612	604
Total equipment rentals
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	10,560				8,705				10,560	8,705
Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									8,761	7,797	8,534
Goodwill and other intangible assets, net	5,637				5,361				5,637	5,361
Domestic  | Property and equipment, net
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	560				558				560	558
Domestic  | Total equipment rentals
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	9,448				7,960				9,448	7,960
Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									955	733	817
Goodwill and other intangible assets, net	506				455				506	455
Foreign | Property and equipment, net
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	52				46				52	46
Foreign | Total equipment rentals
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 1,112				$ 745				1,112	745
Total equipment rentals
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									747	604	676
Revenues									8,207	7,140	7,964
Total equipment rentals | Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									7,430	6,543	7,283
Total equipment rentals | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									777	597	681
Sales of rental equipment
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									968	858	831
Revenues									968	858	831
Sales of rental equipment | Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									873	784	757
Sales of rental equipment | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									95	74	74
Sales of new equipment
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									203	247	268
Revenues									203	247	268
Sales of new equipment | Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									162	218	238
Sales of new equipment | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									41	29	30
Contractor supplies sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									109	98	104
Revenues									109	98	104
Contractor supplies sales | Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									95	86	92
Contractor supplies sales | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									14	12	12
Service and other revenues
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									229	187	184
Revenues									229	187	184
Service and other revenues | Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									201	166	164
Service and other revenues | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from contract with customer, excluding assessed tax									$ 28	$ 21	$ 20