Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Re-rent revenue, Topic 842	$ 30	$ 37	$ 64	$ 72
Ancillary and other rental revenues:
Revenues	1,939	2,290	4,064	4,407
Topic 842
Ancillary and other rental revenues:
Revenues	1,511	1,792	3,148	3,437
Topic 606
Ancillary and other rental revenues:
Revenues	428	498	916	970
Equipment rentals
Ancillary and other rental revenues:
Revenues	1,642	1,960	3,425	3,755
Equipment rentals | Topic 842
Ancillary and other rental revenues:
Revenues	1,511	1,792	3,148	3,437
Equipment rentals | Topic 606
Ancillary and other rental revenues:
Revenues	131	168	277	318
Owned equipment rentals
Revenues:
Owned equipment rentals, Topic 842	1,404	1,668	2,926	3,198
Owned equipment rentals | Topic 842
Revenues:
Owned equipment rentals, Topic 842	1,404	1,668	2,926	3,198
Re-rent revenue
Revenues:
Re-rent revenue, Topic 842	29	37	63	72
Re-rent revenue | Topic 842
Revenues:
Re-rent revenue, Topic 842	29	37	63	72
Ancillary and Other Rental Revenues
Revenues:
Revenue from contract with customer	113	143	232	262
Ancillary and other rental revenues:
Other	96	112	204	223
Revenues	209	255	436	485
Ancillary and Other Rental Revenues | Topic 842
Revenues:
Revenue from contract with customer	0	0	0	0
Ancillary and other rental revenues:
Other	78	87	159	167
Revenues	78	87	159	167
Ancillary and Other Rental Revenues | Topic 606
Revenues:
Revenue from contract with customer	113	143	232	262
Ancillary and other rental revenues:
Other	18	25	45	56
Revenues	131	168	277	318
Sales of rental equipment
Revenues:
Revenue from contract with customer	176	197	384	389
Sales of rental equipment | Topic 606
Revenues:
Revenue from contract with customer	176	197	384	389
Sales of new equipment
Revenues:
Revenue from contract with customer	53	60	115	122
Sales of new equipment | Topic 606
Revenues:
Revenue from contract with customer	53	60	115	122
Contractor supplies sales
Revenues:
Revenue from contract with customer	23	27	48	51
Contractor supplies sales | Topic 606
Revenues:
Revenue from contract with customer	23	27	48	51
Service and other revenues
Revenues:
Revenue from contract with customer	45	46	92	90
Service and other revenues | Topic 606
Revenues:
Revenue from contract with customer	$ 45	$ 46	$ 92	$ 90