Restructuring Charges (Schedule of restructuring charges) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			$ 33
Charged to Costs and Expenses	$ 4	$ 19	6	$ 19
Payments and Other			(17)
Ending Reserve Balance	22		22
Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			21
Charged to Costs and Expenses			1
Payments and Other			(6)
Ending Reserve Balance	16		16
Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			12
Charged to Costs and Expenses			5
Payments and Other			(11)
Ending Reserve Balance	6		6
Closed Restructuring Programs
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			13
Charged to Costs and Expenses			0
Payments and Other			(3)
Ending Reserve Balance	10		10
Closed Restructuring Programs | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			13
Charged to Costs and Expenses			0
Payments and Other			(3)
Ending Reserve Balance	10		10
Closed Restructuring Programs | Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0
Charged to Costs and Expenses			0
Payments and Other			0
Ending Reserve Balance	0		0
NES/Neff/Project XL Restructuring Program
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			20
Charged to Costs and Expenses			6
Payments and Other			(14)
Ending Reserve Balance	12		12
NES/Neff/Project XL Restructuring Program | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			8
Charged to Costs and Expenses			1
Payments and Other			(3)
Ending Reserve Balance	6		6
NES/Neff/Project XL Restructuring Program | Severance and other
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			12
Charged to Costs and Expenses			5
Payments and Other			(11)
Ending Reserve Balance	$ 6		$ 6