REVENUE Disaggregated Revenue - Major Products/Service Lines (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 2,089,338	$ 1,788,028	$ 3,992,805	$ 3,525,011
ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	635,576	604,466	1,262,837	1,204,477
SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	117,723	110,405	232,775	216,645
Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	220,143	190,453	414,610	355,948
Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	158,997	125,175	310,069	253,880
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	21,753	19,379	43,691	37,668
DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	330,622	272,446	629,592	539,076
SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	604,524	465,704	1,099,231	917,317
FMS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,295,453	1,163,579	2,538,032	2,296,049
FMS | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	700,779	662,462	1,391,210	1,318,774
FMS | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	125,266	117,384	247,139	230,993
FMS | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	232,425	199,340	436,955	373,346
FMS | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	215,230	165,014	419,037	335,268
FMS | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	21,753	19,379	43,691	37,668
FMS | DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
FMS | SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	330,622	272,446	629,592	539,076
DTS | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	330,622	272,446	629,592	539,076
DTS | SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	604,524	465,704	1,099,231	917,317
SCS | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0		0
SCS | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0		0
SCS | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0		0
SCS | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0		0
SCS | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
SCS | DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
SCS | SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	604,524	465,704	1,099,231	917,317
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(141,261)	(113,701)	(274,050)	(227,431)
Intersegment Eliminations | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(65,203)	(57,996)	(128,373)	(114,297)
Intersegment Eliminations | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(7,543)	(6,979)	(14,364)	(14,348)
Intersegment Eliminations | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(12,282)	(8,887)	(22,345)	(17,398)
Intersegment Eliminations | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(56,233)	(39,839)	(108,968)	(81,388)
Intersegment Eliminations | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Intersegment Eliminations | DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Intersegment Eliminations | SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0