Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Owned equipment rentals	$ 1,861	$ 1,536	$ 4,951	$ 4,069
Re-rent revenue	41	32	95	78
Ancillary and other rental revenues:
Delivery and pick-up	132	107	336	279
Other	99	77	260	204
Total ancillary and other rental revenues	231	184	596	483
Total equipment rentals	1,861	1,536	4,951	4,069
Service and other revenues	37	30	106	86
Total revenues	2,116	1,766	5,741	4,719
Topic 840
Revenues:
Re-rent revenue	41	32	95	78
Ancillary and other rental revenues:
Delivery and pick-up	0	0	0	0
Other	78	61	198	160
Total ancillary and other rental revenues	78	61	198	160
Total equipment rentals	1,708	1,413	4,553	3,746
Service and other revenues	0	0	0	0
Total revenues	1,708	1,413	4,553	3,746
Topic 606
Revenues:
Re-rent revenue	0		0
Ancillary and other rental revenues:
Delivery and pick-up	132		336
Other	21		62
Total ancillary and other rental revenues	153		398
Total equipment rentals	153		398
Service and other revenues	37		106
Total revenues	408		1,188
Topic 605
Revenues:
Re-rent revenue		0		0
Ancillary and other rental revenues:
Delivery and pick-up		107		279
Other		16		44
Total ancillary and other rental revenues		123		323
Total equipment rentals		123		323
Service and other revenues		30		86
Total revenues		353		973
Owned equipment rentals
Revenues:
Owned equipment rentals	1,589	1,320	4,260	3,508
Owned equipment rentals | Topic 840
Revenues:
Owned equipment rentals	1,589	1,320	4,260	3,508
Owned equipment rentals | Topic 606
Revenues:
Owned equipment rentals	0		0
Owned equipment rentals | Topic 605
Revenues:
Owned equipment rentals		0		0
Rental equipment
Ancillary and other rental revenues:
Sales revenue	140	139	478	378
Rental equipment | Topic 840
Ancillary and other rental revenues:
Sales revenue	0	0	0	0
Rental equipment | Topic 606
Ancillary and other rental revenues:
Sales revenue	140		478
Rental equipment | Topic 605
Ancillary and other rental revenues:
Sales revenue		139		378
New equipment
Ancillary and other rental revenues:
Sales revenue	54	40	140	126
New equipment | Topic 840
Ancillary and other rental revenues:
Sales revenue	0	0	0	0
New equipment | Topic 606
Ancillary and other rental revenues:
Sales revenue	54		140
New equipment | Topic 605
Ancillary and other rental revenues:
Sales revenue		40		126
Contractor supplies
Ancillary and other rental revenues:
Sales revenue	24	21	66	60
Contractor supplies | Topic 840
Ancillary and other rental revenues:
Sales revenue	0	0	0	0
Contractor supplies | Topic 606
Ancillary and other rental revenues:
Sales revenue	$ 24		$ 66
Contractor supplies | Topic 605
Ancillary and other rental revenues:
Sales revenue		$ 21		$ 60