Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Re-rent revenue, Topic 842	$ 42		$ 114
Ancillary and other rental revenues:
Revenues	2,488	$ 2,116	6,895	$ 5,741
Topic 842
Ancillary and other rental revenues:
Revenues	1,967		5,404
Topic 606
Ancillary and other rental revenues:
Revenues	521	408	1,491	1,188
Topic 840
Ancillary and other rental revenues:
Revenues		1,708		4,553
Owned equipment rentals
Revenues:
Owned equipment rentals, Topic 842	1,831		5,029
Owned equipment rentals, Topic 840		1,589		4,260
Owned equipment rentals | Topic 842
Revenues:
Owned equipment rentals, Topic 842	1,831		5,029
Owned equipment rentals | Topic 840
Revenues:
Owned equipment rentals, Topic 840		1,589		4,260
Re-rent revenue
Revenues:
Re-rent revenue, Topic 842	41		113
Re-rent revenue, Topic 840		41		95
Re-rent revenue | Topic 842
Revenues:
Re-rent revenue, Topic 842	41		113
Re-rent revenue | Topic 840
Revenues:
Re-rent revenue, Topic 840		41		95
Equipment rentals
Ancillary and other rental revenues:
Revenues	2,147	1,861	5,902	4,951
Equipment rentals | Topic 842
Ancillary and other rental revenues:
Revenues	1,967		5,404
Equipment rentals | Topic 606
Ancillary and other rental revenues:
Revenues	180	153	498	398
Equipment rentals | Topic 840
Ancillary and other rental revenues:
Revenues		1,708		4,553
Ancillary and Other Rental Revenues
Revenues:
Revenue from contract with customer	156	132	418	336
Ancillary and other rental revenues:
Other	119	99	342	260
Revenues	275	231	760	596
Ancillary and Other Rental Revenues | Topic 842
Revenues:
Revenue from contract with customer	0		0
Ancillary and other rental revenues:
Other	95		262
Revenues	95		262
Ancillary and Other Rental Revenues | Topic 606
Revenues:
Revenue from contract with customer	156	132	418	336
Ancillary and other rental revenues:
Other	24	21	80	62
Revenues	180	153	498	398
Ancillary and Other Rental Revenues | Topic 840
Revenues:
Revenue from contract with customer		0		0
Ancillary and other rental revenues:
Other		78		198
Revenues		78		198
Sales of rental equipment
Revenues:
Revenue from contract with customer	198	140	587	478
Sales of rental equipment | Topic 606
Revenues:
Revenue from contract with customer	198	140	587	478
Sales of new equipment
Revenues:
Revenue from contract with customer	67	54	189	140
Sales of new equipment | Topic 606
Revenues:
Revenue from contract with customer	67	54	189	140
Contractor supplies sales
Revenues:
Revenue from contract with customer	27	24	78	66
Contractor supplies sales | Topic 606
Revenues:
Revenue from contract with customer	27	24	78	66
Service and other revenues
Revenues:
Revenue from contract with customer	49	37	139	106
Service and other revenues | Topic 606
Revenues:
Revenue from contract with customer	$ 49	$ 37	$ 139	$ 106