Quarterly Financial Information (Unaudited) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended			3 Months Ended			3 Months Ended						3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 RSC [Member]	Mar. 31, 2012 RSC [Member]		Dec. 31, 2012 Non Rental Depreciation And Amortization [Member]	Dec. 31, 2012 Interest Expense [Member]	Dec. 31, 2012 10 7/8 percent Senior Notes [Member]	Dec. 31, 2013 1 7/8 percent Convertible Senior Subordinated Notes [Member]	Dec. 31, 2012 1 7/8 percent Convertible Senior Subordinated Notes [Member]	Dec. 31, 2011 1 7/8 percent Convertible Senior Subordinated Notes [Member]	Dec. 31, 2012 Facility Closing [Member]
Effect of Fourth Quarter Events [Line Items]
Increase (decrease) in bad debt expense	$ (17)
RSC merger related costs			9	111	19	13
Restructuring charge			12	99	19										6
Asset impairment charges									2
Stated interest rate											10.875%	1.875%	1.875%	1.875%
Gains (losses) on extinguishment of debt			(1)	(72)	(3)					(72)
Self insurance reserve benefit	3	6
Costs recognized out of period		8
Debt and capital lease obligations	$ 7,173	$ 7,309	$ 7,173	$ 7,309			$ 2,825	[1]

[1] In August 1998, a subsidiary trust of Holdings (the “Trust”) issued and sold $300 of 6 1/2 percent Convertible Quarterly Income Preferred Securities (“QUIPS”) in a private offering. The Trust used the proceeds from the offering to purchase 6 1/2 percent subordinated convertible debentures due 2028 (the “Debentures”), which resulted in Holdings receiving all of the net proceeds of the offering. The QUIPS were non-voting securities, carried a liquidation value of $50 (fifty dollars) per security and were convertible into Holdings’ common stock. During the year ended December 31, 2013, an aggregate of $55 of QUIPS was redeemed. In connection with these redemptions, during the year ended December 31, 2013, we retired $55 principal amount of our subordinated convertible debentures. As of December 31, 2013, there were no QUIPS or subordinated convertible debentures outstanding. Total long-term debt at December 31, 2012 excludes $55 of these Debentures, which were separately classified in our consolidated balance sheets and referred to as “subordinated convertible debentures.” The subordinated convertible debentures reflected the obligation to our subsidiary that issued the QUIPS. This subsidiary was not consolidated in our financial statements because we were not the primary beneficiary of the Trust. As of December 31, 2013, the Trust was liquidated.