Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING BALANCE SHEET (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 257		$ 158		$ 227	$ 175
Accounts receivable, net	848		940
Intercompany receivable (payable)	0		0
Inventory	81		78
Prepaid expenses and other assets	51		122
Deferred taxes	215		248
Total current assets	1,452		1,546
Investments in subsidiaries	0		0
Goodwill	3,249		3,272
Other intangible assets, net	1,047		1,106
Other long-term assets	118		97
Total assets	12,282		12,467
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	593	[1]	618	[1]
Accounts payable	465		285
Accrued expenses and other liabilities	497		575
Total current liabilities	1,555		1,478
Long-term debt	7,482		7,434
Deferred taxes	1,690		1,692
Other long-term liabilities	60		65
Total liabilities	10,787		10,669
Temporary equity	1		2
Total stockholders’ equity (deficit)	1,494		1,796
Total liabilities and stockholders’ equity	12,282		12,467
Parent
Condensed Financial Information Other Details [Abstract]
Ownership percentage in subsidiaries	100.00%
ASSETS
Cash and cash equivalents	0		0		0	0
Accounts receivable, net	0		0
Intercompany receivable (payable)	172		476
Inventory	0		0
Prepaid expenses and other assets	0		0
Deferred taxes	0		0
Total current assets	172		476
Investments in subsidiaries	1,307		1,330
Goodwill	0		0
Other intangible assets, net	0		0
Other long-term assets	0		1
Total assets	1,521		1,849
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	7		32
Accounts payable	0		0
Accrued expenses and other liabilities	0		0
Total current liabilities	7		32
Long-term debt	0		0
Deferred taxes	19		19
Other long-term liabilities	0		0
Total liabilities	26		51
Temporary equity	1		2
Total stockholders’ equity (deficit)	1,494		1,796
Total liabilities and stockholders’ equity	1,521		1,849
URNA
ASSETS
Cash and cash equivalents	58		8		23	17
Accounts receivable, net	37		37
Intercompany receivable (payable)	24		(428)
Inventory	73		69
Prepaid expenses and other assets	43		113
Deferred taxes	214		246
Total current assets	449		45
Investments in subsidiaries	1,479		1,185
Goodwill	3,001		3,000
Other intangible assets, net	967		1,014
Other long-term assets	118		96
Total assets	11,761		11,071
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	586		38
Accounts payable	405		248
Accrued expenses and other liabilities	448		499
Total current liabilities	1,439		785
Long-term debt	7,356		7,298
Deferred taxes	1,599		1,594
Other long-term liabilities	60		64
Total liabilities	10,454		9,741
Temporary equity	0		0
Total stockholders’ equity (deficit)	1,307		1,330
Total liabilities and stockholders’ equity	11,761		11,071
Guarantor Subsidiaries
Condensed Financial Information Other Details [Abstract]
Ownership percentage in subsidiaries	100.00%
ASSETS
Cash and cash equivalents	0		0		0	0
Accounts receivable, net	0		0
Intercompany receivable (payable)	(185)		(60)
Inventory	0		0
Prepaid expenses and other assets	0		1
Deferred taxes	0		0
Total current assets	(185)		(59)
Investments in subsidiaries	968		1,040
Goodwill	0		0
Other intangible assets, net	0		0
Other long-term assets	0		0
Total assets	804		1,002
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	0		0
Accounts payable	0		0
Accrued expenses and other liabilities	15		19
Total current liabilities	15		19
Long-term debt	120		130
Deferred taxes	0		0
Other long-term liabilities	0		0
Total liabilities	135		149
Temporary equity	0		0
Total stockholders’ equity (deficit)	669		853
Total liabilities and stockholders’ equity	804		1,002
Non Guarantor Subsidiaries - Foreign
ASSETS
Cash and cash equivalents	199		150		204	158
Accounts receivable, net	113		144
Intercompany receivable (payable)	(123)		(109)
Inventory	8		9
Prepaid expenses and other assets	8		8
Deferred taxes	1		2
Total current assets	206		204
Investments in subsidiaries	0		0
Goodwill	248		272
Other intangible assets, net	80		92
Other long-term assets	0		0
Total assets	1,140		1,220
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	0		0
Accounts payable	60		37
Accrued expenses and other liabilities	34		57
Total current liabilities	94		94
Long-term debt	6		6
Deferred taxes	72		79
Other long-term liabilities	0		1
Total liabilities	172		180
Temporary equity	0		0
Total stockholders’ equity (deficit)	968		1,040
Total liabilities and stockholders’ equity	1,140		1,220
Non Guarantor Subsidiaries - SPV
ASSETS
Cash and cash equivalents	0		0		0	0
Accounts receivable, net	698		759
Intercompany receivable (payable)	0		0
Inventory	0		0
Prepaid expenses and other assets	0		0
Deferred taxes	0		0
Total current assets	698		759
Investments in subsidiaries	0		0
Goodwill	0		0
Other intangible assets, net	0		0
Other long-term assets	0		0
Total assets	698		759
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	0		548
Accounts payable	0		0
Accrued expenses and other liabilities	0		0
Total current liabilities	0		548
Long-term debt	0		0
Deferred taxes	0		0
Other long-term liabilities	0		0
Total liabilities	0		548
Temporary equity	0		0
Total stockholders’ equity (deficit)	698		211
Total liabilities and stockholders’ equity	698		759
8 1/4 percent Senior Notes
Condensed Financial Information Other Details [Abstract]
Stated interest rate	8.25%
ABL Facility, Accounts Receivable Securitization Facility, and Other Agreements | URNA
Condensed Financial Information Other Details [Abstract]
Line of credit facility, restricted payment capacity	261
Eliminations
ASSETS
Cash and cash equivalents	0		0		0	0
Accounts receivable, net	0		0
Intercompany receivable (payable)	112		121
Inventory	0		0
Prepaid expenses and other assets	0		0
Deferred taxes	0		0
Total current assets	112		121
Investments in subsidiaries	(3,754)		(3,555)
Goodwill	0		0
Other intangible assets, net	0		0
Other long-term assets	0		0
Total assets	(3,642)		(3,434)
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	0		0
Accounts payable	0		0
Accrued expenses and other liabilities	0		0
Total current liabilities	0		0
Long-term debt	0		0
Deferred taxes	0		0
Other long-term liabilities	0		0
Total liabilities	0		0
Temporary equity	0		0
Total stockholders’ equity (deficit)	(3,642)		(3,434)
Total liabilities and stockholders’ equity	(3,642)		(3,434)
Rental equipment, net
ASSETS
Property, plant and equipment, net	5,988		6,008
Rental equipment, net | Parent
ASSETS
Property, plant and equipment, net	0		0
Rental equipment, net | URNA
ASSETS
Property, plant and equipment, net	5,423		5,399
Rental equipment, net | Guarantor Subsidiaries
ASSETS
Property, plant and equipment, net	0		0
Rental equipment, net | Non Guarantor Subsidiaries - Foreign
ASSETS
Property, plant and equipment, net	565		609
Rental equipment, net | Non Guarantor Subsidiaries - SPV
ASSETS
Property, plant and equipment, net	0		0
Rental equipment, net | Eliminations
ASSETS
Property, plant and equipment, net	0		0
Property and equipment, net
ASSETS
Property, plant and equipment, net	428		438
Property and equipment, net | Parent
ASSETS
Property, plant and equipment, net	42		42
Property and equipment, net | URNA
ASSETS
Property, plant and equipment, net	324		332
Property and equipment, net | Guarantor Subsidiaries
ASSETS
Property, plant and equipment, net	21		21
Property and equipment, net | Non Guarantor Subsidiaries - Foreign
ASSETS
Property, plant and equipment, net	41		43
Property and equipment, net | Non Guarantor Subsidiaries - SPV
ASSETS
Property, plant and equipment, net	0		0
Property and equipment, net | Eliminations
ASSETS
Property, plant and equipment, net	$ 0		$ 0

[1] As of March 31, 2015, our short-term debt primarily reflects the current portion of the debt discussed above that was redeemed in April 2015 using availability under our accounts receivable securitization facility.