REVENUE Disaggregated Revenue - Major Products/Service Lines (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 2,158,061	$ 1,840,897	$ 6,150,866	$ 5,365,908
ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	652,433	616,617	1,920,116	1,825,274
SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	115,432	108,779	343,386	321,246
Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	242,734	206,580	657,328	562,527
Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	156,787	129,087	466,847	382,966
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	21,527	19,127	65,218	56,795
DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	340,604	272,201	970,196	811,277
SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	628,544	488,506	1,727,775	1,405,823
FMS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,336,548	1,195,797	3,874,580	3,491,846
FMS | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	716,728	673,882	2,107,938	1,992,656
FMS | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	125,850	116,985	372,989	347,978
FMS | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	257,909	216,016	694,864	589,362
FMS | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	214,534	169,787	633,571	505,055
FMS | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	21,527	19,127	65,218	56,795
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	340,604	272,201	970,196	811,277
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	340,604	272,201	970,196	811,277
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	628,544	488,506	1,727,775	1,405,823
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	628,544	488,506	1,727,775	1,405,823
Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(147,635)	(115,607)	(421,685)	(343,038)
Eliminations | ChoiceLease
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(64,295)	(57,265)	(187,822)	(167,382)
Eliminations | SelectCare
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(10,418)	(8,206)	(29,603)	(26,732)
Eliminations | Commercial rental
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(15,175)	(9,436)	(37,536)	(26,835)
Eliminations | Fuel
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(57,747)	(40,700)	(166,724)	(122,089)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Eliminations | DTS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Eliminations | SCS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0