Debt (Schedule of Long Term Debt) (Details) (USD $)																																																																							1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Accounts Receivable Securitization Facility [Member]	Dec. 31, 2013 $2.3 billion ABL Facility [Member]	Dec. 31, 2013 5 3/4 percent Senior Secured Notes [Member]	Mar. 31, 2012 5 3/4 percent Senior Secured Notes [Member]	Dec. 31, 2013 10 1/4 percent Senior Notes [Member]	Dec. 31, 2013 9 1/4 percent Senior Notes [Member]	Nov. 30, 2009 9 1/4 percent Senior Notes [Member]	Dec. 31, 2013 7 3/8 percent Senior Notes [Member]	Mar. 31, 2012 7 3/8 percent Senior Notes [Member]	Dec. 31, 2013 8 3/8 percent Senior Subordinated Notes [Member]	Oct. 30, 2010 8 3/8 percent Senior Subordinated Notes [Member]	Dec. 31, 2013 8 1/4 percent Senior Notes [Member]	Dec. 31, 2013 7 5/8 percent Senior Notes [Member]	Mar. 31, 2012 7 5/8 percent Senior Notes [Member]	Dec. 31, 2013 6 1/8 percent Senior Notes [Member]	Oct. 31, 2012 6 1/8 percent Senior Notes [Member]	Dec. 31, 2013 4 percent Convertible Senior Notes [Member]	Dec. 31, 2012 4 percent Convertible Senior Notes [Member]	Dec. 31, 2011 4 percent Convertible Senior Notes [Member]	Nov. 30, 2009 4 percent Convertible Senior Notes [Member]	Dec. 31, 2013 6 1/2 Subordinated Convertible Debentures [Member]	Dec. 31, 2012 6 1/2 Subordinated Convertible Debentures [Member]	Dec. 31, 2013 Convertible Quarterly Income Preferred Securities [Member]	Dec. 31, 2013 Subsidiaries [Member]	Dec. 31, 2012 Subsidiaries [Member]	Dec. 31, 2013 Subsidiaries [Member] Accounts Receivable Securitization Facility [Member]		Dec. 31, 2012 Subsidiaries [Member] Accounts Receivable Securitization Facility [Member]		Dec. 31, 2013 Subsidiaries [Member] $2.3 billion ABL Facility [Member]		Dec. 31, 2012 Subsidiaries [Member] $2.3 billion ABL Facility [Member]		Dec. 31, 2013 Subsidiaries [Member] 5 3/4 percent Senior Secured Notes [Member]		Dec. 31, 2012 Subsidiaries [Member] 5 3/4 percent Senior Secured Notes [Member]		Dec. 31, 2013 Subsidiaries [Member] 10 1/4 percent Senior Notes [Member]		Dec. 31, 2012 Subsidiaries [Member] 10 1/4 percent Senior Notes [Member]		Dec. 31, 2013 Subsidiaries [Member] 9 1/4 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 9 1/4 percent Senior Notes [Member]	Dec. 31, 2013 Subsidiaries [Member] 7 3/8 percent Senior Notes [Member]		Dec. 31, 2012 Subsidiaries [Member] 7 3/8 percent Senior Notes [Member]		Dec. 31, 2013 Subsidiaries [Member] 8 3/8 percent Senior Subordinated Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 8 3/8 percent Senior Subordinated Notes [Member]	Dec. 31, 2013 Subsidiaries [Member] 8 1/4 percent Senior Notes [Member]		Dec. 31, 2012 Subsidiaries [Member] 8 1/4 percent Senior Notes [Member]		Dec. 31, 2013 Subsidiaries [Member] 7 5/8 percent Senior Notes [Member]		Dec. 31, 2012 Subsidiaries [Member] 7 5/8 percent Senior Notes [Member]		Dec. 31, 2013 Subsidiaries [Member] 6 1/8 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 6 1/8 percent Senior Notes [Member]	Dec. 31, 2013 Subsidiaries [Member] Capital leases [Member]		Dec. 31, 2012 Subsidiaries [Member] Capital leases [Member]		Dec. 31, 2013 Parent Company [Member]	Dec. 31, 2012 Parent Company [Member]	Dec. 31, 2013 Parent Company [Member] 4 percent Convertible Senior Notes [Member]		Dec. 31, 2012 Parent Company [Member] 4 percent Convertible Senior Notes [Member]	Aug. 31, 1998 QUIPS [Member]	Dec. 31, 2013 QUIPS [Member]
Debt Instrument [Line Items]
Total debt	$ 7,173,000,000	$ 7,309,000,000																								$ 7,037,000,000	$ 7,172,000,000	$ 430,000,000	[1]	$ 453,000,000	[1]	$ 1,106,000,000	[1]	$ 1,184,000,000	[1]	$ 750,000,000	[2]	$ 750,000,000	[2]	$ 220,000,000	[3]	$ 223,000,000	[3]	$ 494,000,000	$ 494,000,000	$ 750,000,000	[2]	$ 750,000,000	[2]	$ 750,000,000	$ 750,000,000	$ 692,000,000	[3]	$ 695,000,000	[3]	$ 1,325,000,000	[2]	$ 1,325,000,000	[2]	$ 400,000,000	$ 400,000,000	$ 120,000,000	[3]	$ 148,000,000	[3]			$ 136,000,000	[4]	$ 137,000,000
Less short-term portion	(604,000,000)	(630,000,000)
Long-term debt	6,569,000,000	6,679,000,000																																																																0	0
Stated interest rate					5.75%		10.25%	9.25%		7.375%		8.375%		8.25%	7.625%		6.125%		4.00%	4.00%	4.00%	4.00%	6.50%		6.50%
Line of credit facility, maximum borrowing capacity																																2,300,000,000.0
Debt instrument, face amount						750,000,000			500,000,000		750,000,000		750,000,000			1,325,000,000		400,000,000	173,000,000			173,000,000
Unused borrowing capacity amount			53,000,000	1,142,000,000
Letters of credit outstanding				52,000,000
Interest rate at period end			0.80%	2.50%
Proceeds from issuance of private placement																																																																							300,000,000
Preferred stock, liquidation preference per share																																																																								$ 50
Subordinated convertible debentures	$ 0	$ 55,000,000																						$ 55,000,000																																										$ 0	$ 55,000,000

[1] $1,142 and $53 were available under our ABL facility and accounts receivable securitization facility, respectively, at December 31, 2013. The ABL facility availability is reflected net of $52 of letters of credit. At December 31, 2013, the interest rates applicable to our ABL facility and accounts receivable securitization facility were 2.5 percent and 0.8 percent, respectively.

[2] 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.

[3] Upon consummation of the RSC merger, we assumed certain of RSC's debt, including capital leases. See below for additional detail regarding the assumed RSC debt.

[4] The fair value of the 4 percent Convertible Senior Notes is based on the market value of comparable notes. Consistent with the carrying amount, the fair value excludes the equity component of the notes. To exclude the equity component and calculate the fair value, we used an effective interest rate of 6.6 percent. As discussed below (see note 12), the total cost to settle the notes based on the closing price of our common stock on December 31, 2013 would be $1,094.