Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING BALANCE SHEETS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 352	$ 312	$ 179	$ 158
Accounts receivable, net	1,233	920
Intercompany receivable (payable)	0	0
Inventory	75	68
Prepaid expenses and other assets	112	61
Total current assets	1,772	1,361
Rental equipment, net	7,824	6,189
Property and equipment, net	467	430
Investments in subsidiaries	0	0
Goodwill	4,082	3,260	3,243	3,272
Other intangible assets, net	875	742
Other long-term assets	10	6
Total assets	15,030	11,988	12,083
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	723	597
Accounts payable	409	243
Accrued expenses and other liabilities	536	344
Total current liabilities	1,668	1,184
Long-term debt	8,717	7,193
Deferred taxes	1,419	1,896
Other long-term liabilities	120	67
Total liabilities	11,924	10,340
Total stockholders’ equity (deficit)	3,106	1,648
Total liabilities and stockholders’ equity	15,030	11,988
Eliminations
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	112	104
Inventory	0	0
Prepaid expenses and other assets	(224)	0
Total current assets	(112)	104
Rental equipment, net	0	0
Property and equipment, net	0	0
Investments in subsidiaries	(4,429)	(3,283)
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	0	0
Total assets	(4,541)	(3,179)
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)	(4,541)	(3,179)
Total liabilities and stockholders’ equity	(4,541)	(3,179)
Parent | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	887	336
Inventory	0	0
Prepaid expenses and other assets	4	5
Total current assets	891	341
Rental equipment, net	0	0
Property and equipment, net	41	38
Investments in subsidiaries	2,194	1,292
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	3	0
Total assets	3,129	1,671
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	2
Deferred taxes	21	20
Other long-term liabilities	0	0
Total liabilities	23	23
Total stockholders’ equity (deficit)	3,106	1,648
Total liabilities and stockholders’ equity	$ 3,129	1,671
URNA
Condensed Financial Information Other Details [Abstract]
Ownership percentage in subsidiaries	100.00%
URNA | Reportable Legal Entities
ASSETS
Cash and cash equivalents	$ 23	21	18	8
Accounts receivable, net	56	38
Intercompany receivable (payable)	(677)	(137)
Inventory	68	61
Prepaid expenses and other assets	219	51
Total current assets	(311)	34
Rental equipment, net	7,264	5,709
Property and equipment, net	352	326
Investments in subsidiaries	1,148	1,013
Goodwill	3,815	3,013
Other intangible assets, net	827	686
Other long-term assets	7	6
Total assets	13,102	10,787
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	25	25
Accounts payable	366	217
Accrued expenses and other liabilities	477	305
Total current liabilities	868	547
Long-term debt	8,596	7,076
Deferred taxes	1,324	1,805
Other long-term liabilities	120	67
Total liabilities	10,908	9,495
Total stockholders’ equity (deficit)	2,194	1,292
Total liabilities and stockholders’ equity	$ 13,102	10,787
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)	(198)	(188)
Inventory	0	0
Prepaid expenses and other assets	111	0
Total current assets	(87)	(188)
Rental equipment, net	0	0
Property and equipment, net	32	26
Investments in subsidiaries	1,087	978
Goodwill	0	0
Other intangible assets, net	0	0
Other long-term assets	0	0
Total assets	1,032	816
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	17	13
Total current liabilities	17	13
Long-term debt	117	111
Deferred taxes	0	0
Other long-term liabilities	0	0
Total liabilities	134	124
Total stockholders’ equity (deficit)	898	692
Total liabilities and stockholders’ equity	1,032	816
Foreign | Reportable Legal Entities
ASSETS
Cash and cash equivalents	329	291	161	150
Accounts receivable, net	119	96
Intercompany receivable (payable)	(124)	(115)
Inventory	7	7
Prepaid expenses and other assets	2	5
Total current assets	333	284
Rental equipment, net	560	480
Property and equipment, net	42	40
Investments in subsidiaries	0	0
Goodwill	267	247
Other intangible assets, net	48	56
Other long-term assets	0	0
Total assets	1,250	1,107
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	2	3
Accounts payable	43	26
Accrued expenses and other liabilities	41	25
Total current liabilities	86	54
Long-term debt	3	4
Deferred taxes	74	71
Other long-term liabilities	0	0
Total liabilities	163	129
Total stockholders’ equity (deficit)	1,087	978
Total liabilities and stockholders’ equity	1,250	1,107
SPV | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	1,058	786
Intercompany receivable (payable)	0	0
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	1,058	786
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	1,058	786
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	695	568
Accounts payable	0	0
Accrued expenses and other liabilities	1	1
Total current liabilities	696	569
Long-term debt	0	0
Deferred taxes	0	0
Other long-term liabilities	0	0
Total liabilities	696	569
Total stockholders’ equity (deficit)	362	217
Total liabilities and stockholders’ equity	1,058	$ 786
ABL facility
Condensed Financial Information Other Details [Abstract]
Line of credit facility, restricted payment capacity	1,869
ABL facility | URNA
Condensed Financial Information Other Details [Abstract]
Line of credit facility, restricted payment capacity	$ 982
Senior notes | 5 3/4 percent Senior Notes due 2024
Condensed Financial Information Other Details [Abstract]
Stated interest rate	5.75%