Restructuring Charges (Schedule of restructuring charges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			$ 17
Charged to Costs and Expenses	$ 9	$ 4	28	$ 8
Payments and Other			(21)
Ending Reserve Balance	24		24
Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			16
Charged to Costs and Expenses			8
Payments and Other			(4)
Ending Reserve Balance	20		20
Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			1
Charged to Costs and Expenses			20
Payments and Other			(17)
Ending Reserve Balance	4		4
Closed Restructuring Programs
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			17
Charged to Costs and Expenses			1
Payments and Other			(4)
Ending Reserve Balance	14		14
Closed Restructuring Programs | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			16
Charged to Costs and Expenses			1
Payments and Other			(3)
Ending Reserve Balance	14		14
Closed Restructuring Programs | Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			1
Charged to Costs and Expenses			0
Payments and Other			(1)
Ending Reserve Balance	0		0
NES/Neff/Project XL Restructuring Program
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0
Charged to Costs and Expenses			27
Payments and Other			(17)
Ending Reserve Balance	10		10
NES/Neff/Project XL Restructuring Program | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0
Charged to Costs and Expenses			7
Payments and Other			(1)
Ending Reserve Balance	6		6
NES/Neff/Project XL Restructuring Program | Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0
Charged to Costs and Expenses			20
Payments and Other			(16)
Ending Reserve Balance	$ 4		$ 4