Segment Information (Geographic area information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	$ 3,455		$ 2,151		$ 1,834
Sales of rental equipment																	399		208		144
Sales of new equipment																	93		84		78
Contractor supplies sales																	87		85		95
Service and other revenues																	83		83		86
Total revenues	1,249	[1]	1,219	[1]	993	[1]	656	[1]	746	[2]	713	[2]	629	[2]	523	[2]	4,117	[1]	2,611	[2]	2,237
Rental equipment, net	4,966								2,617								4,966		2,617
Property and equipment, net	428								366								428		366
Goodwill and other intangible assets, net	4,170								372								4,170		372
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	2,948		1,779		1,569
Sales of rental equipment																	350		180		121
Sales of new equipment																	67		59		59
Contractor supplies sales																	67		62		71
Service and other revenues																	66		64		68
Total revenues																	3,498		2,144		1,888
Rental equipment, net	4,357								2,181								4,357		2,181
Property and equipment, net	390								338								390		338
Goodwill and other intangible assets, net	3,804								232								3,804		232
Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment rentals																	507		372		265
Sales of rental equipment																	49		28		23
Sales of new equipment																	26		25		19
Contractor supplies sales																	20		23		24
Service and other revenues																	17		19		18
Total revenues																	619		467		349
Rental equipment, net	609								436								609		436
Property and equipment, net	38								28								38		28
Goodwill and other intangible assets, net	$ 366								$ 140								$ 366		$ 140

[1] During the fourth quarter of 2012, we recognized $13 of charges related to the RSC merger. Additionally, during the quarter, we recognized restructuring charges of $6, primarily reflecting branch closure charges associated with the RSC merger. 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 includes $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 is no impact on 2012 full year operating income.

[2] During the fourth quarter of 2011, we recognized $19 of charges associated with the RSC acquisition. Additionally, during the quarter, we closed 18 branches and recognized restructuring charges of $14. During the quarter, we also recognized asset impairment charges of $3 which are primarily reflected in non-rental depreciation and amortization and principally relate to write-offs of leasehold improvements and other fixed assets in connection with our closed restructuring program. In the quarter, we also purchased an aggregate of $32 of QUIPS for $32. In connection with this transaction, we retired $32 principal amount of our subordinated convertible debentures and recognized a loss of $1 in interest expense-subordinated convertible debentures, net, inclusive of the write-off of capitalized debt issuance costs. Interest expense, net for the fourth quarter of 2011 also includes a loss of $3 reflecting write-offs of debt issuance costs associated with the amendment of our ABL facility discussed above. During the quarter, we also recognized a benefit of $8 in cost of equipment rentals, excluding depreciation related to our provision for self-insurance reserves.