Restructuring Charges (Schedule of restructuring charges) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Restructuring Reserve [Roll Forward]
Beginning reserve balance				$ 20
Charged to Costs and Expenses		$ 0	$ (2)	1	[1]	$ (2)
Payments and Other				(7)
Ending reserve balance		14		14
Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning reserve balance				20
Charged to Costs and Expenses	[1]			1
Payments and Other				(7)
Ending reserve balance		14		14
Severance costs
Restructuring Reserve [Roll Forward]
Beginning reserve balance				0
Charged to Costs and Expenses	[1]			0
Payments and Other				0
Ending reserve balance		0		0
Closed Restructuring Program
Restructuring Reserve [Roll Forward]
Beginning reserve balance				9
Charged to Costs and Expenses	[1]			1
Payments and Other				(3)
Ending reserve balance		7		7
Closed Restructuring Program | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning reserve balance				9
Charged to Costs and Expenses	[1]			1
Payments and Other				(3)
Ending reserve balance		7		7
Closed Restructuring Program | Severance costs
Restructuring Reserve [Roll Forward]
Beginning reserve balance				0
Charged to Costs and Expenses	[1]			0
Payments and Other				0
Ending reserve balance		0		0
RSC Merger Related Restructuring Program
Restructuring Reserve [Roll Forward]
Beginning reserve balance				11
Charged to Costs and Expenses	[1]			0
Payments and Other				(4)
Ending reserve balance		7		7
RSC Merger Related Restructuring Program | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning reserve balance				11
Charged to Costs and Expenses	[1]			0
Payments and Other				(4)
Ending reserve balance		7		7
RSC Merger Related Restructuring Program | Severance costs
Restructuring Reserve [Roll Forward]
Beginning reserve balance				0
Charged to Costs and Expenses	[1]			0
Payments and Other				0
Ending reserve balance		$ 0		$ 0

[1] Reflected in our condensed consolidated statements of income as “Restructuring charge.” These charges are not allocated to our reportable segments.