REVENUE Disaggregated Revenue - Major Products/Service Lines (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,244,993	$ 2,089,904	$ 4,425,320	$ 3,994,109
ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	694,765	638,447	1,375,152	1,268,972
SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	124,549	115,425	248,077	227,954
Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	239,068	220,143	458,240	414,609
Fuel
Disaggregation of Revenue [Line Items]
Total revenue	152,060	158,990	300,780	310,060
Other
Disaggregation of Revenue [Line Items]
Total revenue	22,996	21,753	46,224	43,691
DTS
Disaggregation of Revenue [Line Items]
Total revenue	362,244	330,622	711,865	629,592
SCS
Disaggregation of Revenue [Line Items]
Total revenue	649,311	604,524	1,284,982	1,099,231
FMS
Disaggregation of Revenue [Line Items]
Total revenue	1,233,438	1,154,758	2,428,473	2,265,286
DTS
Disaggregation of Revenue [Line Items]
Total revenue	362,244	330,622	711,865	629,592
SCS
Disaggregation of Revenue [Line Items]
Total revenue	649,311	604,524	1,284,982	1,099,231
Operating Segments | FMS
Disaggregation of Revenue [Line Items]
Total revenue	1,390,910	1,295,729	2,742,509	2,538,779
Operating Segments | FMS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	765,312	701,055	1,513,890	1,391,957
Operating Segments | FMS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	136,360	125,266	272,139	247,139
Operating Segments | FMS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	253,871	232,425	490,019	436,955
Operating Segments | FMS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	212,371	215,230	420,237	419,037
Operating Segments | FMS | Other
Disaggregation of Revenue [Line Items]
Total revenue	22,996	21,753	46,224	43,691
Operating Segments | FMS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | FMS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS
Disaggregation of Revenue [Line Items]
Total revenue	362,244	330,622	711,865	629,592
Operating Segments | DTS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | DTS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	362,244	330,622	711,865	629,592
Operating Segments | DTS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS
Disaggregation of Revenue [Line Items]
Total revenue	649,311	604,524	1,284,982	1,099,231
Operating Segments | SCS | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | SCS | SCS
Disaggregation of Revenue [Line Items]
Total revenue	649,311	604,524	1,284,982	1,099,231
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue	(157,472)	(140,971)	(314,036)	(273,493)
Eliminations | ChoiceLease
Disaggregation of Revenue [Line Items]
Total revenue	(70,547)	(62,608)	(138,738)	(122,985)
Eliminations | SelectCare
Disaggregation of Revenue [Line Items]
Total revenue	(11,811)	(9,841)	(24,062)	(19,185)
Eliminations | Commercial rental
Disaggregation of Revenue [Line Items]
Total revenue	(14,803)	(12,282)	(31,779)	(22,346)
Eliminations | Fuel
Disaggregation of Revenue [Line Items]
Total revenue	(60,311)	(56,240)	(119,457)	(108,977)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Eliminations | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Eliminations | SCS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Eliminations | FMS
Disaggregation of Revenue [Line Items]
Total revenue	157,472	140,971	314,036	273,493
Eliminations | DTS
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Eliminations | SCS
Disaggregation of Revenue [Line Items]
Total revenue	$ 0	$ 0	$ 0	$ 0