Condensed Consolidating Financial Information of Guarantor Subsidiaries - CONDENSED CONSOLIDATING BALANCE SHEET (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 52	$ 43	$ 278	$ 352
Accounts receivable, net	1,487	1,545
Intercompany receivable (payable)	0	0
Inventory	123	109
Prepaid expenses and other assets	58	64
Total current assets	1,720	1,761
Investments in subsidiaries	0	0
Goodwill	5,121	5,058
Other intangible assets, net	1,089	1,084
Operating lease right-of-use assets	622	0
Other long-term assets	16	16
Total assets	18,586	18,133
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	930	903
Accounts payable	557	536
Accrued expenses and other liabilities	751	677
Total current liabilities	2,238	2,116
Long-term debt	10,676	10,844
Deferred taxes	1,714	1,687
Operating lease liabilities	497	0
Other long-term liabilities	86	83
Total liabilities	15,211	14,730
Total stockholders’ equity (deficit)	3,375	3,403
Total liabilities and stockholders’ equity (deficit)	18,586	18,133
Eliminations
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	0	0
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	0	0
Investments in subsidiaries	(4,259)	(4,452)
Goodwill	0	0
Other intangible assets, net	0	0
Operating lease right-of-use assets	0
Other long-term assets	0	0
Total assets	(4,259)	(4,452)
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
Operating lease liabilities	0
Other long-term liabilities	0	0
Total liabilities	0	0
Total stockholders’ equity (deficit)	(4,259)	(4,452)
Total liabilities and stockholders’ equity (deficit)	(4,259)	(4,452)
Parent | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	1,661	1,534
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	1,661	1,534
Investments in subsidiaries	1,668	1,826
Goodwill	0	0
Other intangible assets, net	0	0
Operating lease right-of-use assets	0
Other long-term assets	9	9
Total assets	3,397	3,426
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	0	1
Accounts payable	0	0
Accrued expenses and other liabilities	0	0
Total current liabilities	0	1
Long-term debt	0	0
Deferred taxes	21	22
Operating lease liabilities	0
Other long-term liabilities	1	0
Total liabilities	22	23
Total stockholders’ equity (deficit)	3,375	3,403
Total liabilities and stockholders’ equity (deficit)	3,397	3,426
URNA | Reportable Legal Entities
ASSETS
Cash and cash equivalents	24	1	49	23
Accounts receivable, net	0	0
Intercompany receivable (payable)	(1,552)	(1,423)
Inventory	111	96
Prepaid expenses and other assets	53	60
Total current assets	(1,364)	(1,266)
Investments in subsidiaries	1,588	1,646
Goodwill	4,743	4,661
Other intangible assets, net	1,010	1,004
Operating lease right-of-use assets	548
Other long-term assets	7	7
Total assets	15,689	15,424
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	47	50
Accounts payable	504	481
Accrued expenses and other liabilities	686	619
Total current liabilities	1,237	1,150
Long-term debt	10,654	10,778
Deferred taxes	1,609	1,587
Operating lease liabilities	436
Other long-term liabilities	85	83
Total liabilities	14,021	13,598
Total stockholders’ equity (deficit)	1,668	1,826
Total liabilities and stockholders’ equity (deficit)	15,689	15,424
Guarantor Subsidiaries | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivable (payable)	(99)	(96)
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	(99)	(96)
Investments in subsidiaries	1,003	980
Goodwill	0	0
Other intangible assets, net	0	0
Operating lease right-of-use assets	0
Other long-term assets	0	0
Total assets	943	924
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	10	14
Total current liabilities	10	14
Long-term debt	9	9
Deferred taxes	0	0
Operating lease liabilities	0
Other long-term liabilities	0	0
Total liabilities	19	23
Total stockholders’ equity (deficit)	924	901
Total liabilities and stockholders’ equity (deficit)	943	924
Non-Guarantor Subsidiaries - Foreign | Reportable Legal Entities
ASSETS
Cash and cash equivalents	28	42	229	329
Accounts receivable, net	149	159
Intercompany receivable (payable)	(11)	(15)
Inventory	12	13
Prepaid expenses and other assets	5	4
Total current assets	183	203
Investments in subsidiaries	0	0
Goodwill	378	397
Other intangible assets, net	79	80
Operating lease right-of-use assets	74
Other long-term assets	0	0
Total assets	1,477	1,425
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	2	2
Accounts payable	53	55
Accrued expenses and other liabilities	52	42
Total current liabilities	107	99
Long-term debt	13	57
Deferred taxes	84	78
Operating lease liabilities	61
Other long-term liabilities	0	0
Total liabilities	265	234
Total stockholders’ equity (deficit)	1,212	1,191
Total liabilities and stockholders’ equity (deficit)	1,477	1,425
Non Guarantor Subsidiaries- SPV | Reportable Legal Entities
ASSETS
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	1,338	1,386
Intercompany receivable (payable)	1	0
Inventory	0	0
Prepaid expenses and other assets	0	0
Total current assets	1,339	1,386
Investments in subsidiaries	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Operating lease right-of-use assets	0
Other long-term assets	0	0
Total assets	1,339	1,386
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Short-term debt and current maturities of long-term debt	881	850
Accounts payable	0	0
Accrued expenses and other liabilities	3	2
Total current liabilities	884	852
Long-term debt	0	0
Deferred taxes	0	0
Operating lease liabilities	0
Other long-term liabilities	0	0
Total liabilities	884	852
Total stockholders’ equity (deficit)	455	534
Total liabilities and stockholders’ equity (deficit)	1,339	1,386
Rental equipment, net
ASSETS
Property and equipment, net	9,438	9,600
Rental equipment, net | Eliminations
ASSETS
Property and equipment, net	0	0
Rental equipment, net | Parent | Reportable Legal Entities
ASSETS
Property and equipment, net	0	0
Rental equipment, net | URNA | Reportable Legal Entities
ASSETS
Property and equipment, net	8,736	8,910
Rental equipment, net | Guarantor Subsidiaries | Reportable Legal Entities
ASSETS
Property and equipment, net	0	0
Rental equipment, net | Non-Guarantor Subsidiaries - Foreign | Reportable Legal Entities
ASSETS
Property and equipment, net	702	690
Rental equipment, net | Non Guarantor Subsidiaries- SPV | Reportable Legal Entities
ASSETS
Property and equipment, net	0	0
Property and equipment, net
ASSETS
Property and equipment, net	580	614
Property and equipment, net | Eliminations
ASSETS
Property and equipment, net	0	0
Property and equipment, net | Parent | Reportable Legal Entities
ASSETS
Property and equipment, net	59	57
Property and equipment, net | URNA | Reportable Legal Entities
ASSETS
Property and equipment, net	421	462
Property and equipment, net | Guarantor Subsidiaries | Reportable Legal Entities
ASSETS
Property and equipment, net	39	40
Property and equipment, net | Non-Guarantor Subsidiaries - Foreign | Reportable Legal Entities
ASSETS
Property and equipment, net	61	55
Property and equipment, net | Non Guarantor Subsidiaries- SPV | Reportable Legal Entities
ASSETS
Property and equipment, net	$ 0	$ 0