Quarterly Financial Information (Unaudited) (Details) (USD $) In Millions, except Per Share data, 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
Selected Quarterly Financial Information [Abstract]
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
Gross profit	567	[1]	564	[1]	471	[1]	385	[1]	495	[2]	505	[2]	374	[2]	213	[2]	1,987	[1]	1,587	[2]	898
Operating income	342	[1]	337	[1]	250	[1]	149	[1]	236	[2]	222	[2]	46	[2]	87	[2]	1,078	[1]	591	[2]	396
Net income (loss)	$ 140	[1]	$ 143	[1]	$ 83	[1]	$ 21	[1]	$ 41	[2]	$ 73	[2]	$ (52)	[2]	$ 13	[2]	$ 387	[1]	$ 75	[2]	$ 101
Basic earnings per share (in dollars per share)	$ 1.49	[1]	$ 1.53	[1]	$ 0.89	[1]	$ 0.22	[1]	$ 0.45	[2]	$ 0.78	[2]	$ (0.63)	[2]	$ 0.21	[2]	$ 4.14	[1]	$ 0.91	[2]	$ 1.62
Diluted earnings per share (in dollars per share)	$ 1.31	[1],[3]	$ 1.35	[1],[3]	$ 0.78	[1],[3]	$ 0.19	[1],[3]	$ 0.40	[2],[3]	$ 0.70	[2],[3]	$ (0.63)	[2],[3]	$ 0.17	[2],[3]	$ 3.64	[1],[3]	$ 0.79	[2],[3]	$ 1.38
Earnings Per Share, Diluted, Other Disclosures [Abstract]
RSC merger related costs (4)	$ 0.00	[4]	$ 0.00	[4]	$ (0.01)	[4]	$ (0.03)	[4]	$ (0.08)	[4]	$ (0.05)	[4]	$ (0.60)	[4]	$ (0.09)	[4]	$ (0.05)	[4]	$ (0.72)	[4]
RSC merger related intangible asset amortization (5)	$ (0.24)	[5]	$ (0.23)	[5]	$ (0.24)	[5]	$ (0.24)	[5]	$ (0.25)	[5]	$ (0.25)	[5]	$ (0.21)	[5]	$ 0.00	[5]	$ (0.94)	[5]	$ (0.74)	[5]
Impact on depreciation related to acquired RSC fleet and property and equipment (6)	$ 0.01	[6]	$ 0.01	[6]	$ 0.01	[6]	$ 0.01	[6]	$ 0.00	[6]	$ 0.02	[6]	$ 0.02	[6]	$ 0.00	[6]	$ 0.04	[6]	$ 0.03	[6]
Impact of the fair value mark-up of acquired RSC fleet and inventory (7)	$ (0.06)	[7]	$ (0.05)	[7]	$ (0.07)	[7]	$ (0.08)	[7]	$ (0.09)	[7]	$ (0.09)	[7]	$ (0.05)	[7]	$ 0.00	[7]	$ (0.25)	[7]	$ (0.24)	[7]
Pre-close RSC merger related interest expense (8)									$ 0.00	[8]	$ 0.00	[8]	$ (0.12)	[8]	$ (0.10)	[8]			$ (0.19)	[8]
Impact on interest expense related to fair value adjustment of acquired RSC indebtedness (9)	$ 0.01	[9]	$ 0.01	[9]	$ 0.01	[9]	$ 0.01	[9]	$ 0.01	[9]	$ 0.01	[9]	$ 0.01	[9]	$ 0.00	[9]	$ 0.04	[9]	$ 0.03	[9]
Restructuring charge (10)	$ 0.00	[10]	$ (0.01)	[10]	$ (0.03)	[10]	$ (0.04)	[10]	$ (0.03)	[10]	$ (0.23)	[10]	$ (0.39)	[10]	$ 0.00	[10]	$ (0.07)	[10]	$ (0.64)	[10]
Asset impairment charge (11)	$ 0.00	[11]	$ 0.00	[11]	$ (0.01)	[11]	$ (0.01)	[11]	$ (0.01)	[11]	$ (0.06)	[11]	$ (0.02)	[11]	$ 0.00	[11]	$ (0.02)	[11]	$ (0.10)	[11]
Loss on extinguishment of debt securities, including subordinated convertible debentures	$ 0.00		$ (0.01)		$ 0.00		$ (0.01)		$ (0.41)		$ 0.00		$ 0.00		$ 0.00		$ (0.02)		$ (0.45)
Gain on sale of software subsidiary (13)									$ (0.01)	[12]	$ 0.00	[12]	$ 0.07	[12]	$ 0.00	[12]			$ 0.05	[12]

[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.

[3] Diluted earnings (loss) per share includes the after-tax impacts of the following: First Quarter Second Quarter Third Quarter Fourth Quarter Full YearFor the year ended December 31, 2013: RSC merger related costs (4)$(0.03) $(0.01) $— $— $(0.05)RSC merger related intangible asset amortization (5)(0.24) (0.24) (0.23) (0.24) (0.94)Impact on depreciation related to acquired RSC fleet and property and equipment (6)0.01 0.01 0.01 0.01 0.04Impact of the fair value mark-up of acquired RSC fleet and inventory (7)(0.08) (0.07) (0.05) (0.06) (0.25)Impact on interest expense related to fair value adjustment of acquired RSC indebtedness (9)0.01 0.01 0.01 0.01 0.04Restructuring charge (10)(0.04) (0.03) (0.01) — (0.07)Asset impairment charge (11)(0.01) (0.01) — — (0.02)Loss on extinguishment of debt securities, including subordinated convertible debentures(0.01) — (0.01) — (0.02)For the year ended December 31, 2012: RSC merger related costs (4)$(0.09) $(0.60) $(0.05) $(0.08) $(0.72)RSC merger related intangible asset amortization (5)— (0.21) (0.25) (0.25) (0.74)Impact on depreciation related to acquired RSC fleet and property and equipment (6)— 0.02 0.02 — 0.03Impact of the fair value mark-up of acquired RSC fleet and inventory (7)— (0.05) (0.09) (0.09) (0.24)Pre-close RSC merger related interest expense (8)(0.10) (0.12) — — (0.19)Impact on interest expense related to fair value adjustment of acquired RSC indebtedness (9)— 0.01 0.01 0.01 0.03Restructuring charge (10)— (0.39) (0.23) (0.03) (0.64)Asset impairment charge (11)— (0.02) (0.06) (0.01) (0.10)Loss on extinguishment of debt securities, including subordinated convertible debentures— — — (0.41) (0.45)Gain on sale of software subsidiary (12)— 0.07 — (0.01) 0.05

[4] This reflects transaction costs associated with the RSC acquisition discussed in note 3 to our consolidated financial statements.

[5] This reflects the amortization of the intangible assets acquired in the RSC acquisition.

[6] This reflects the impact of extending the useful lives of equipment acquired in the RSC acquisition, net of the impact of additional depreciation associated with the fair value mark-up of such equipment.

[7] This reflects additional costs recorded in cost of rental equipment sales, cost of equipment rentals, excluding depreciation, and cost of contractor supplies sales associated with the fair value mark-up of rental equipment and inventory acquired in the RSC acquisition. The costs relate to equipment and inventory acquired in the RSC acquisition and subsequently sold.

[8] As discussed in note 12 to our consolidated financial statements, in March 2012, we issued $2,825 of debt in connection with the RSC merger. The pre-close RSC merger related interest expense reflects the interest expense recorded on this debt prior to the acquisition date.

[9] This reflects a reduction of interest expense associated with the fair value mark-up of debt acquired in the RSC acquisition. See note 12 to our consolidated financial statements for additional detail on the acquired debt.

[10] As discussed in note 5 to our consolidated financial statements, this reflects severance costs and branch closure charges associated with the RSC merger and our closed restructuring program.

[11] As discussed in note 5 to our consolidated financial statements, this charge primarily reflects write-offs of leasehold improvements and other fixed assets in connection with the RSC acquisition and our closed restructuring program.

[12] This reflects a gain recognized upon the sale of a former subsidiary that developed and marketed software.