Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Re-rent revenue, Topic 842	$ 42	$ 30	$ 74	$ 64
Revenues	2,287	1,939	4,344	4,064
Topic 842
Revenues:
Revenues	1,777	1,511	3,295	3,148
Topic 606
Revenues:
Revenues	510	428	1,049	916
Equipment rentals
Revenues:
Revenues	1,951	1,642	3,618	3,425
Equipment rentals | Topic 842
Revenues:
Revenues	1,777	1,511	3,295	3,148
Equipment rentals | Topic 606
Revenues:
Revenues	174	131	323	277
Owned equipment rentals
Revenues:
Owned equipment rentals, Topic 842	1,635	1,404	3,040	2,926
Owned equipment rentals | Topic 842
Revenues:
Owned equipment rentals, Topic 842	1,635	1,404	3,040	2,926
Re-rent revenue
Revenues:
Re-rent revenue, Topic 842	42	29	74	63
Re-rent revenue | Topic 842
Revenues:
Re-rent revenue, Topic 842	42	29	74	63
Ancillary and Other Rental Revenues
Revenues:
Revenue from contract with customer	148	113	264	232
Other	126	96	240	204
Revenues	274	209	504	436
Ancillary and Other Rental Revenues | Topic 842
Revenues:
Revenue from contract with customer	0	0	0	0
Other	100	78	181	159
Revenues	100	78	181	159
Ancillary and Other Rental Revenues | Topic 606
Revenues:
Revenue from contract with customer	148	113	264	232
Other	26	18	59	45
Revenues	174	131	323	277
Sales of rental equipment
Revenues:
Revenue from contract with customer	194	176	461	384
Sales of rental equipment | Topic 606
Revenues:
Revenue from contract with customer	194	176	461	384
Sales of new equipment
Revenues:
Revenue from contract with customer	57	53	106	115
Sales of new equipment | Topic 606
Revenues:
Revenue from contract with customer	57	53	106	115
Contractor supplies sales
Revenues:
Revenue from contract with customer	27	23	51	48
Contractor supplies sales | Topic 606
Revenues:
Revenue from contract with customer	27	23	51	48
Service and other revenues
Revenues:
Revenue from contract with customer	58	45	108	92
Service and other revenues | Topic 606
Revenues:
Revenue from contract with customer	$ 58	$ 45	$ 108	$ 92