Debt (Schedule of long-term debt instruments) (Details) (USD $)	9 Months Ended							1 Months Ended									9 Months Ended	1 Months Ended		1 Months Ended		1 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013		Sep. 30, 2014 5 3/4 percent Senior Secured Notes	Sep. 30, 2014 10 1/4 percent Senior Notes	Apr. 30, 2014 9 1/4 percent Senior Notes	Sep. 30, 2014 9 1/4 percent Senior Notes	Sep. 30, 2014 7 3/8 percent Senior Notes	Sep. 30, 2014 8 3/8 percent Senior Subordinated Notes	Sep. 30, 2014 8 1/4 percent Senior Notes	Sep. 30, 2014 7 5/8 percent Senior Notes	Sep. 30, 2014 6 1/8 percent Senior Notes	Sep. 30, 2014 5 3/4 percent Senior Notes	Sep. 30, 2014 Convertible subordinated notes—4 percent	Sep. 30, 2014 Credit facility $2.3 billion ABL Facility	Jan. 31, 2014 Senior notes 10 1/4 percent Senior Notes	Sep. 30, 2014 Senior notes 6 1/8 percent Senior Notes	Mar. 31, 2014 Senior notes Add-on to 6 1/8 percent Senior Notes	Sep. 30, 2014 Senior notes Add-on to 6 1/8 percent Senior Notes	Mar. 31, 2014 Senior notes 5 3/4 percent Senior Notes	Mar. 31, 2014 Senior notes 12-month period commencing on or after May 15, 2019 5 3/4 percent Senior Notes	Mar. 31, 2014 Senior notes 12-month period commencing on or after May 15, 2022 5 3/4 percent Senior Notes	Sep. 30, 2014 Accounts receivable facility Accounts Receivable Securitization Facility	Sep. 30, 2014 Convertible senior notes Convertible subordinated notes—4 percent		Dec. 31, 2013 Convertible senior notes Convertible subordinated notes—4 percent		Nov. 30, 2009 Convertible senior notes Convertible subordinated notes—4 percent	Sep. 30, 2014 URNA and subsidiaries	Dec. 31, 2013 URNA and subsidiaries	Sep. 30, 2014 URNA and subsidiaries $2.3 billion ABL Facility	Sep. 30, 2014 URNA and subsidiaries Capital leases	Dec. 31, 2013 URNA and subsidiaries Capital leases	Sep. 30, 2014 URNA and subsidiaries Credit facility $2.3 billion ABL Facility		Dec. 31, 2013 URNA and subsidiaries Credit facility $2.3 billion ABL Facility		Sep. 30, 2014 URNA and subsidiaries Senior secured notes 5 3/4 percent Senior Secured Notes	Dec. 31, 2013 URNA and subsidiaries Senior secured notes 5 3/4 percent Senior Secured Notes	Sep. 30, 2014 URNA and subsidiaries Senior notes 10 1/4 percent Senior Notes		Dec. 31, 2013 URNA and subsidiaries Senior notes 10 1/4 percent Senior Notes		Sep. 30, 2014 URNA and subsidiaries Senior notes 9 1/4 percent Senior Notes		Dec. 31, 2013 URNA and subsidiaries Senior notes 9 1/4 percent Senior Notes		Sep. 30, 2014 URNA and subsidiaries Senior notes 7 3/8 percent Senior Notes	Dec. 31, 2013 URNA and subsidiaries Senior notes 7 3/8 percent Senior Notes	Sep. 30, 2014 URNA and subsidiaries Senior notes 8 1/4 percent Senior Notes	Dec. 31, 2013 URNA and subsidiaries Senior notes 8 1/4 percent Senior Notes	Sep. 30, 2014 URNA and subsidiaries Senior notes 7 5/8 percent Senior Notes	Dec. 31, 2013 URNA and subsidiaries Senior notes 7 5/8 percent Senior Notes	Sep. 30, 2014 URNA and subsidiaries Senior notes 6 1/8 percent Senior Notes		Dec. 31, 2013 URNA and subsidiaries Senior notes 6 1/8 percent Senior Notes		Sep. 30, 2014 URNA and subsidiaries Senior notes 5 3/4 percent Senior Notes		Dec. 31, 2013 URNA and subsidiaries Senior notes 5 3/4 percent Senior Notes		Sep. 30, 2014 URNA and subsidiaries Senior subordinated notes 8 3/8 percent Senior Subordinated Notes	Dec. 31, 2013 URNA and subsidiaries Senior subordinated notes 8 3/8 percent Senior Subordinated Notes	Sep. 30, 2014 URNA and subsidiaries Accounts receivable facility Accounts Receivable Securitization Facility		Dec. 31, 2013 URNA and subsidiaries Accounts receivable facility Accounts Receivable Securitization Facility
Debt Instrument
Total debt	$ 8,095,000,000			$ 7,173,000,000																						$ 31,000,000	[1]	$ 136,000,000	[1]		$ 8,064,000,000	$ 7,037,000,000		$ 114,000,000	$ 120,000,000	$ 1,336,000,000	[2]	$ 1,106,000,000	[2]	$ 750,000,000	$ 750,000,000	$ 0	[3]	$ 220,000,000	[3]	$ 0	[4]	$ 494,000,000	[4]	$ 750,000,000	$ 750,000,000	$ 688,000,000	$ 692,000,000	$ 1,325,000,000	$ 1,325,000,000	$ 951,000,000	[5]	$ 400,000,000	[5]	$ 850,000,000	[6]	$ 0	[6]	$ 750,000,000	$ 750,000,000	$ 550,000,000	[7]	$ 430,000,000	[7]
Less short-term portion	(618,000,000)	[8]		(604,000,000)	[8]
Total long-term debt	7,477,000,000			6,569,000,000
Stated interest rate						5.75%	10.25%		9.25%	7.375%	8.375%	8.25%	7.625%	6.125%	5.75%											4.00%
Interest rate at end of period																7.10%			5.70%
Average outstanding amount under facility																									449,000,000
Maximum borrowing capacity																																	2,300,000,000.0
Weighted average interest rate, short-term																									0.80%
A/R Securitization maximum month-end outstanding amount																									550,000,000
Collateral amount																									634,000,000
Current borrowing capacity under credit facility																	908,000,000								0
Letters of credit outstanding																	56,000,000
Credit facility interest rate at period end																	2.20%								0.80%
Average outstanding amount																	1,100,000,000
Weighted average interest rate, long-term																	2.30%
ABL Facility maximum month-end outstanding amount																	1,300,000,000
Debt redemption, call premium amount								52,000,000										26,000,000
Gain (loss) on extinguishment of debt securities	(80,000,000)		(1,000,000)					(64,000,000)										(6,000,000)								(10,000,000)
Face amount																			925,000,000	525,000,000		850,000,000				34,000,000				173,000,000
Unamortized premium																					26,000,000
Proceeds from debt	5,911,000,000		2,931,000,000																	546,000,000		837,000,000
Debt redemption price, percentage																						101.00%	102.875%	100.00%
Unamortized discount																										3,000,000
Extinguishment of debt, amount																										$ 122,000,000
Convertible, conversion price (in dollars per share)																										$ 11.11

[1] The difference between the September 30, 2014 carrying value of the 4 percent Convertible Senior Notes and the $34 principal amount reflects the $3 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 September 30, 2014, an amount equal to the $3 unamortized portion of the original issue discount is separately classified in our condensed consolidated balance sheets and referred to as “temporary equity.” During the nine months ended September 30, 2014, $122 of our 4 percent Convertible Notes were redeemed. We recognized a loss of approximately $10 in interest expense, net upon redemption. The loss represented the difference between the net carrying amount and the fair value of the debt component of the notes. Based on the price of our common stock during the third quarter of 2014, holders of the 4 percent Convertible Senior Notes have the right to redeem the notes during the fourth quarter of 2014 at a conversion price of $11.11 per share of common stock. Since October 1, 2014 (the beginning of the fourth quarter), none of the 4 percent Convertible Senior Notes were redeemed.

[2] At September 30, 2014, $908 was available under our ABL facility, net of $56 of letters of credit. The interest rate applicable to the ABL facility was 2.2 percent at September 30, 2014. During the nine months ended September 30, 2014, the monthly average amount outstanding under the ABL facility was $1.1 billion, and the weighted-average interest rate thereon was 2.3 percent. The maximum month-end amount outstanding under the ABL facility during the nine months ended September 30, 2014 was $1.3 billion.

[3] In January 2014, we redeemed all of our 10 1/4 percent Senior Notes. We paid a call premium of $26 in connection with the redemption, and recognized a loss of approximately $6 in interest expense, net upon redemption. The loss represented the difference between the net carrying amount and the total purchase price of the notes.

[4] As discussed in note 2 to our condensed consolidated financial statements, in April 2014, we completed the acquisition of assets of National Pump. Using proceeds from debt issued in connection with the National Pump acquisition, as discussed below, and cash on hand, we redeemed all the outstanding 9 1/4 percent Senior Notes in April 2014. We paid a call premium of approximately $52 in connection with the redemption and recognized a loss of approximately $64 in interest expense upon redemption. The loss represented the difference between the net carrying amount and the total purchase price of the notes.

[5] In connection with the National Pump acquisition described above, in March 2014, URNA issued $525 principal amount of 6 1/8 percent Senior Notes as an add on to our existing 6 1/8 percent Senior Notes. The net proceeds from the issuance were $546 (after deducting offering expenses). The newly issued notes have identical terms, and are fungible, with the 6 1/8 percent Senior Notes outstanding at December 31, 2013. The difference between the carrying value of the 6 1/8 percent Senior Notes and the $925 principal amount relates to the $26 unamortized portion of the original issue premium recognized in conjunction with the March 2014 issuance, which is being amortized through the maturity date in 2023. The effective interest rate on the 6 1/8 percent Senior Notes is 5.7 percent.

[6] In connection with the National Pump acquisition described above, in March 2014, URNA issued $850 principal amount of 5 3/4 percent Senior Notes which are due November 15, 2024. The net proceeds from the issuance were $837 (after deducting offering expenses). The net proceeds were used to finance in part the cash purchase price of the National Pump acquisition which closed in April 2014. The 5 3/4 percent Senior Notes are unsecured and are guaranteed by Holdings and, subject to limited exceptions, URNA's domestic subsidiaries. The 5 3/4 percent Senior Notes may be redeemed on or after May 15, 2019, at specified redemption prices that range from 102.875 percent in the 12-month period commencing on May 15, 2019, to 100 percent in the 12-month period commencing on May 15, 2022 and thereafter, plus accrued and unpaid interest. The indenture governing the 5 3/4 percent Senior Notes contains certain restrictive covenants, including, among others, limitations on (1) liens; (2) additional indebtedness; (3) mergers, consolidations and acquisitions; (4) sales, transfers and other dispositions of assets; (5) loans and other investments; (6) dividends and other distributions, stock repurchases and redemptions and other restricted payments; (7) restrictions affecting subsidiaries; (8) transactions with affiliates; and (9) designations of unrestricted subsidiaries, as well as a requirement to timely file periodic reports with the SEC. Each of these covenants is subject to important exceptions and qualifications that would allow URI to engage in these activities under certain conditions. The indenture also requires that, in the event of a change of control (as defined in the indenture), URI must make an offer to purchase all of the then-outstanding 5 3/4 percent Senior Notes tendered at a purchase price in cash equal to 101 percent of the principal amount thereof, plus accrued and unpaid interest, if any, thereon.

[7] In September 2014, we amended our accounts receivable securitization facility primarily to extend the expiration date of the facility until September 17, 2015. At September 30, 2014, $0 was available under our accounts receivable securitization facility. The interest rate applicable to the accounts receivable securitization facility was 0.8 percent at September 30, 2014. During the nine months ended September 30, 2014, the monthly average amount outstanding under the accounts receivable securitization facility was $449, and the weighted-average interest rate thereon was 0.8 percent. The maximum month-end amount outstanding under the accounts receivable securitization facility during the nine months ended September 30, 2014 was $550. 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 September 30, 2014, there were $634 of receivables, net of applicable reserves, in the collateral pool.

[8] As of September 30, 2014, our short-term debt primarily reflects $550 of borrowings under our accounts receivable securitization facility and $31 of 4 percent Convertible Senior Notes. The 4 percent Convertible Senior Notes mature in November 2015, but are reflected as short-term debt because they were redeemable at September 30, 2014.