Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING BALANCE SHEET (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 278	$ 352	$ 337	$ 312
Accounts receivable, net	1,154	1,233
Intercompany receivable (payable)	0	0
Inventory	84	75
Prepaid expenses and other assets	74	112
Total current assets	1,590	1,772
Rental equipment, net	7,678	7,824
Property and equipment, net	467	467
Investments in subsidiaries	0	0
Goodwill	4,115	4,082
Other intangible assets, net	825	875
Other long-term assets	13	10
Total assets	14,688	15,030
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	726	723
Accounts payable	513	409
Accrued expenses and other liabilities	402	536
Total current liabilities	1,641	1,668
Long-term debt	8,412	8,717
Deferred taxes	1,455	1,419
Other long-term liabilities	122	120
Total liabilities	11,630	11,924
Total stockholders’ equity (deficit)	3,058	3,106
Total liabilities and stockholders’ equity (deficit)	14,688	15,030
Eliminations
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	0	112
Inventory	0	0
Prepaid expenses and other assets	0	(224)
Total current assets	0	(112)
Rental equipment, net	0	0
Property and equipment, net	0	0
Investments in subsidiaries	(4,270)	(4,429)
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	0	0
Total assets	(4,270)	(4,541)
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
Total stockholders’ equity (deficit)	(4,270)	(4,541)
Total liabilities and stockholders’ equity (deficit)	(4,270)	(4,541)
Parent | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	982	887
Inventory	0	0
Prepaid expenses and other assets	0	4
Total current assets	982	891
Rental equipment, net	0	0
Property and equipment, net	42	41
Investments in subsidiaries	2,051	2,194
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	6	3
Total assets	3,081	3,129
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	1	1
Accounts payable	0	0
Accrued expenses and other liabilities	0	0
Total current liabilities	1	1
Long-term debt	1	1
Deferred taxes	21	21
Other long-term liabilities	0	0
Total liabilities	23	23
Total stockholders’ equity (deficit)	3,058	3,106
Total liabilities and stockholders’ equity (deficit)	$ 3,081	3,129
URNA
Condensed Financial Information Other Details [Abstract]
Ownership percentage in subsidiaries	100.00%
URNA | Reportable Legal Entities
ASSETS
Cash and cash equivalents	$ 49	23	14	21
Accounts receivable, net	69	56
Intercompany receivable (payable)	(878)	(677)
Inventory	76	68
Prepaid expenses and other assets	73	219
Total current assets	(611)	(311)
Rental equipment, net	7,140	7,264
Property and equipment, net	351	352
Investments in subsidiaries	1,154	1,148
Goodwill	3,855	3,815
Other intangible assets, net	781	827
Other long-term assets	7	7
Total assets	12,677	13,102
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	24	25
Accounts payable	470	366
Accrued expenses and other liabilities	354	477
Total current liabilities	848	868
Long-term debt	8,294	8,596
Deferred taxes	1,362	1,324
Other long-term liabilities	122	120
Total liabilities	10,626	10,908
Total stockholders’ equity (deficit)	2,051	2,194
Total liabilities and stockholders’ equity (deficit)	$ 12,677	13,102
Guarantor Subsidiaries
Condensed Financial Information Other Details [Abstract]
Ownership percentage in subsidiaries	100.00%
Guarantor Subsidiaries | Reportable Legal Entities
ASSETS
Cash and cash equivalents	$ 0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	(92)	(198)
Inventory	0	0
Prepaid expenses and other assets	0	111
Total current assets	(92)	(87)
Rental equipment, net	0	0
Property and equipment, net	34	32
Investments in subsidiaries	1,065	1,087
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	0	0
Total assets	1,007	1,032
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	14	17
Total current liabilities	14	17
Long-term debt	114	117
Deferred taxes	0	0
Other long-term liabilities	0	0
Total liabilities	128	134
Total stockholders’ equity (deficit)	879	898
Total liabilities and stockholders’ equity (deficit)	1,007	1,032
Non-Guarantor Subsidiaries - Foreign | Reportable Legal Entities
ASSETS
Cash and cash equivalents	229	329	323	291
Accounts receivable, net	109	119
Intercompany receivable (payable)	(12)	(124)
Inventory	8	7
Prepaid expenses and other assets	1	2
Total current assets	335	333
Rental equipment, net	538	560
Property and equipment, net	40	42
Investments in subsidiaries	0	0
Goodwill	260	267
Other intangible assets, net	44	48
Other long-term assets	0	0
Total assets	1,217	1,250
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	2	2
Accounts payable	43	43
Accrued expenses and other liabilities	32	41
Total current liabilities	77	86
Long-term debt	3	3
Deferred taxes	72	74
Other long-term liabilities	0	0
Total liabilities	152	163
Total stockholders’ equity (deficit)	1,065	1,087
Total liabilities and stockholders’ equity (deficit)	1,217	1,250
Non-Guarantor Subsidiaries - SPV | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	976	1,058
Intercompany receivable (payable)	0	0
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	976	1,058
Rental equipment, net	0	0
Property and equipment, net	0	0
Investments in subsidiaries	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	0	0
Total assets	976	1,058
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	699	695
Accounts payable	0	0
Accrued expenses and other liabilities	2	1
Total current liabilities	701	696
Long-term debt	0	0
Deferred taxes	0	0
Other long-term liabilities	0	0
Total liabilities	701	696
Total stockholders’ equity (deficit)	275	362
Total liabilities and stockholders’ equity (deficit)	976	$ 1,058
ABL Facility
Condensed Financial Information Other Details [Abstract]
Line of credit facility, restricted payment capacity	1,882
ABL Facility | URNA
Condensed Financial Information Other Details [Abstract]
Line of credit facility, restricted payment capacity	$ 900
Senior notes | 5 3/4 percent Senior Notes due 2024
Condensed Financial Information Other Details [Abstract]
Stated interest rate	5.75%