Debt and Subordinated Convertible Debentures (Schedule of long-term debt instruments) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified					3 Months Ended												3 Months Ended																																				1 Months Ended				0 Months Ended
	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2013 Accounts Receivable Securitization Facility [Member]	Mar. 31, 2013 1.9 billion dollar ABL Facility [Member]	Mar. 31, 2013 5 3/4 percent Senior Secured Notes [Member]	Mar. 31, 2013 10 1/4 percent Senior Notes [Member]	Mar. 31, 2013 9 1/4 percent Senior Notes [Member]	Mar. 31, 2013 7 3/8 percent Senior Notes [Member]	Mar. 31, 2013 8 3/8 percent Senior Subordinated Notes [Member]	Mar. 31, 2013 8 1/4 percent Senior Notes [Member]	Mar. 31, 2013 7 5/8 percent Senior Notes [Member]	Mar. 31, 2013 6 1/8 percent Senior Notes [Member]	Mar. 31, 2013 4 percent Convertible Subordinated Notes [Member]	Nov. 30, 2009 4 percent Convertible Subordinated Notes [Member]	Mar. 31, 2013 6 1/2 percent Subordinated Convertible Debentures [Member]	Dec. 31, 2012 6 1/2 percent Subordinated Convertible Debentures [Member]	Mar. 31, 2013 Subsidiaries [Member] Accounts Receivable Securitization Facility [Member]		Dec. 31, 2012 Subsidiaries [Member] Accounts Receivable Securitization Facility [Member]		Mar. 31, 2013 Subsidiaries [Member] 1.9 billion dollar ABL Facility [Member]		Dec. 31, 2012 Subsidiaries [Member] 1.9 billion dollar ABL Facility [Member]		Mar. 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]	Mar. 31, 2013 Subsidiaries [Member] 10 1/4 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 10 1/4 percent Senior Notes [Member]	Mar. 31, 2013 Subsidiaries [Member] 9 1/4 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 9 1/4 percent Senior Notes [Member]	Mar. 31, 2013 Subsidiaries [Member] 7 3/8 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 7 3/8 percent Senior Notes [Member]	Mar. 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]	Mar. 31, 2013 Subsidiaries [Member] 8 1/4 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 8 1/4 percent Senior Notes [Member]	Mar. 31, 2013 Subsidiaries [Member] 7 5/8 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 7 5/8 percent Senior Notes [Member]	Mar. 31, 2013 Subsidiaries [Member] 6 1/8 percent Senior Notes [Member]	Dec. 31, 2012 Subsidiaries [Member] 6 1/8 percent Senior Notes [Member]	Mar. 31, 2013 Subsidiaries [Member] Capital Leases [Member]	Dec. 31, 2012 Subsidiaries [Member] Capital Leases [Member]	Mar. 31, 2013 Subsidiaries [Member] Total URNA and subsidiaries debt [Member]	Dec. 31, 2012 Subsidiaries [Member] Total URNA and subsidiaries debt [Member]	Mar. 31, 2013 Parent Company [Member]	Dec. 31, 2012 Parent Company [Member]	Mar. 31, 2013 Parent Company [Member] 4 percent Convertible Subordinated Notes [Member]		Dec. 31, 2012 Parent Company [Member] 4 percent Convertible Subordinated Notes [Member]		Aug. 31, 1998 QUIPS [Member]	Mar. 31, 2013 QUIPS [Member]	Dec. 31, 2012 Original Terms [Member] Accounts Receivable Securitization Facility [Member]	Mar. 31, 2013 Amended Terms [Member] Accounts Receivable Securitization Facility [Member]	Apr. 15, 2013 Subsequent Event [Member] 6 1/2 percent Subordinated Convertible Debentures [Member]
Debt Instrument [Line Items]
Total debt	$ 7,147	[1]	$ 7,309	[1]															$ 390	[2]	$ 453	[2]	$ 1,091	[3]	$ 1,184	[3]	$ 750	$ 750	$ 222	$ 223	$ 494	$ 494	$ 750	$ 750	$ 750	$ 750	$ 695	$ 695	$ 1,325	$ 1,325	$ 400	$ 400	$ 141	$ 148	$ 7,008	$ 7,172			$ 139	[4]	$ 137	[4]
Less short-term portion	(567)	[5]	(630)	[5]																																											(139)	(137)
Total long-term debt	6,580		6,679																																												0	0
Maximum borrowing capacity																																																							475	550
Unused borrowing capacity under facility					60	748
Interest rate at end of period					0.80%	2.30%
Average outstanding amount under facility					412
Weighted average interest rate					0.80%	2.30%
A/R Securitization maximum month-end outstanding amount					435
Collateral amount					451
Letters of credit outstanding						61
Average outstanding amount						1,014
ABL Facility maximum month-end outstanding amount						1,091
Convertible, conversion price (in dollars per share)															$ 11.11
Stated interest rate							5.75%	10.25%	9.25%	7.375%	8.375%	8.25%	7.625%	6.125%	4.00%		6.50%
Proceeds from Issuance of Private Placement																																																					300
Face amount															168	173							1,900
Unamortized discount															29
Liquidation value (in dollars per security)																																																						$ 50
Extinguishment of debt																	38																																								2
Gains (losses) on extinguishment of debt (Less than $1)																	(1)
Subordinated convertible debentures	$ 17		$ 55														$ 17	$ 55																													$ 17	$ 55

[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 are non-voting securities, carry a liquidation value of $50 (fifty dollars) per security and are convertible into Holdings’ common stock. During the three months ended March 31, 2013, an aggregate of $38 of QUIPS was converted into Holdings' common stock. In connection with this transaction, we retired $38 principal amount of our subordinated convertible debentures and recognized a loss of $1, inclusive of the write-off of capitalized debt issuance costs. This loss is reflected in interest expense-subordinated convertible debentures in our condensed consolidated statements of income. Since April 1, 2013 (the beginning of the second quarter), an additional $2 of QUIPS was converted into Holdings' common stock. Total debt at March 31, 2013 and December 31, 2012 excludes $17 and $55 of these Debentures, respectively, which are separately classified in our condensed consolidated balance sheets and referred to as “subordinated convertible debentures.” The subordinated convertible debentures reflect the obligation to our subsidiary that has issued the QUIPS. This subsidiary is not consolidated in our financial statements because we are not the primary beneficiary of the Trust.

[2] In February 2013, we amended our accounts receivable securitization facility to increase the facility size from $475 to $550. An additional purchaser was also added to the facility, and the facility was not otherwise amended. At March 31, 2013, $60 was available under our accounts receivable securitization facility. The interest rate applicable to the accounts receivable securitization facility was 0.8 percent at March 31, 2013. During the three months ended March 31, 2013, the monthly average amount outstanding under the accounts receivable securitization facility, including the former facility and the amended facility, was $412, and the weighted-average interest rate thereon was 0.8 percent. The maximum month-end amount outstanding under the accounts receivable securitization facility, including the former facility and the amended facility, during the three months ended March 31, 2013 was $435. Borrowings under the accounts receivable securitization facility are permitted only to the extent that the face amount of the receivables in the collateral pool, net of applicable reserves, exceeds the outstanding loans. As of March 31, 2013, there were $451 of receivables, net of applicable reserves, in the collateral pool.

[3] At March 31, 2013, $748 was available under our ABL facility, net of $61 of letters of credit. The interest rate applicable to the ABL facility was 2.3 percent at March 31, 2013. During the three months ended March 31, 2013, the monthly average amount outstanding under the ABL facility was $1,014, and the weighted-average interest rate thereon was 2.3 percent. The maximum month-end amount outstanding under the ABL facility during the three months ended March 31, 2013 was $1,091.

[4] The difference between the March 31, 2013 carrying value of the 4 percent Convertible Senior Notes and the $168 principal amount reflects the $29 unamortized portion of the original issue discount recognized upon issuance of the notes, which is being amortized through the maturity date of November 15, 2015. Because the 4 percent Convertible Senior Notes were redeemable at March 31, 2013, an amount equal to the $29 unamortized portion of the original issue discount is separately classified in our condensed consolidated balance sheets and referred to as “temporary equity.” Based on the price of our common stock during the first quarter of 2013, holders of the 4 percent Convertible Senior Notes have the right to redeem the notes during the second quarter of 2013 at a conversion price of $11.11 per share of common stock. Since April 1, 2013 (the beginning of the second quarter), none of the 4 percent Convertible Senior Notes were redeemed.

[5] As of March 31, 2013, our short-term debt primarily reflects $390 of borrowings under our accounts receivable securitization facility and $139 of 4 percent Convertible Senior Notes. The 4 percent Convertible Senior Notes mature in 2015, but are reflected as short-term debt because they are redeemable at March 31, 2013.