REVENUE Disaggregated Revenue - Major Products/Service Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,180,327	$ 1,904,205
ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	680,388	630,525
SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	123,529	112,529
Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	219,171	194,466
Fuel
Disaggregation of Revenue [Line Items]
Total revenue	148,720	151,070
Other
Disaggregation of Revenue [Line Items]
Total revenue	23,227	21,938
DTS
Disaggregation of Revenue [Line Items]
Total revenue	349,621	298,970
SCS
Disaggregation of Revenue [Line Items]
Total revenue	635,671	494,707
FMS
Disaggregation of Revenue [Line Items]
Total revenue	1,195,035	1,110,528
DTS
Disaggregation of Revenue [Line Items]
Total revenue	349,621	298,970
SCS
Disaggregation of Revenue [Line Items]
Total revenue	635,671	494,707
Operating Segments | FMS
Disaggregation of Revenue [Line Items]
Total revenue	1,351,599	1,243,050
Operating Segments | FMS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	748,579	690,902
Operating Segments | FMS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	135,779	121,873
Operating Segments | FMS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	236,148	204,530
Operating Segments | FMS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	207,866	203,807
Operating Segments | FMS | Other
Disaggregation of Revenue [Line Items]
Total revenue	23,227	21,938
Operating Segments | FMS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | FMS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS
Disaggregation of Revenue [Line Items]
Total revenue	349,621	298,970
Operating Segments | DTS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | DTS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	349,621	298,970
Operating Segments | DTS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS
Disaggregation of Revenue [Line Items]
Total revenue	635,671	494,707
Operating Segments | SCS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | SCS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	635,671	494,707
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue	(156,564)	(132,522)
Eliminations | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	(68,191)	(60,377)
Eliminations | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	(12,250)	(9,344)
Eliminations | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	(16,977)	(10,064)
Eliminations | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	(59,146)	(52,737)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Eliminations | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Eliminations | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Eliminations | FMS
Disaggregation of Revenue [Line Items]
Total revenue	156,564	132,522
Eliminations | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Eliminations | SCS
Disaggregation of Revenue [Line Items]
Total revenue	$ 0	$ 0