Segment Information (Geographic area information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	$ 4,196		$ 3,455		$ 2,151
Sales of rental equipment																	490		399		208
Sales of new equipment																	104		93		84
Contractor supplies sales																	87		87		85
Service and other revenues																	78		83		83
Total revenues	1,338	[1]	1,311	[1]	1,206	[1]	1,100	[1]	1,249	[2]	1,219	[2]	993	[2]	656	[2]	4,955	[1]	4,117	[2]	2,611
Rental equipment, net	5,374								4,966								5,374		4,966
Property and equipment, net	421								428								421		428
Goodwill, net	3,971								4,170								3,971		4,170
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	3,612		2,948		1,779
Sales of rental equipment																	438		350		180
Sales of new equipment																	82		67		59
Contractor supplies sales																	70		67		62
Service and other revenues																	62		66		64
Total revenues																	4,264		3,498		2,144
Rental equipment, net	4,768								4,357								4,768		4,357
Property and equipment, net	381								390								381		390
Goodwill, net	3,639								3,804								3,639		3,804
Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	584		507		372
Sales of rental equipment																	52		49		28
Sales of new equipment																	22		26		25
Contractor supplies sales																	17		20		23
Service and other revenues																	16		17		19
Total revenues																	691		619		467
Rental equipment, net	606								609								606		609
Property and equipment, net	40								38								40		38
Goodwill, net	$ 332								$ 366								$ 332		$ 366

[1] The fourth quarter of 2013 includes a reduction in bad debt expense of $17 as compared to the fourth quarter of 2012 primarily due to improved receivable aging. In the fourth quarter of 2013, we recognized a benefit of $3 in cost of equipment rentals, excluding depreciation related to our provision for self-insurance reserves.

[2] During the fourth quarter of 2012, we recognized $13 of charges associated with the RSC acquisition. Additionally, during the quarter, we recognized restructuring charges of $6, primarily reflecting branch closure charges associated with the RSC acquisition. During the quarter, we also recognized asset impairment charges of $2 which are primarily reflected in non-rental depreciation and amortization and principally relate to write-offs of leasehold improvements and other fixed assets. During the fourth quarter of 2012, we redeemed our 10 7/8 percent Senior Notes and all of our outstanding 1 7/8 percent Convertible Senior Subordinated Notes were converted. Upon redemption/conversion, we recognized a loss of $72 in interest expense, net. The loss represents the difference between the net carrying amount and the total purchase/conversion price of these securities. During the quarter, we also recognized a benefit of $6 in cost of equipment rentals, excluding depreciation related to our provision for self-insurance reserves. Additionally, operating income for the fourth quarter 2012 included $8 of costs, in the aggregate, primarily related to the merger, which should have been recognized in the second and third quarters of 2012. There was no impact on 2012 full year operating income.