REVENUE Disaggregation of Revenue - Geographical (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
U.S.
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,813,746	1,543,711	3,457,110	3,049,366
Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	117,919	105,020	230,408	207,540
Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	85,090	78,709	172,746	155,096
Mexico
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	66,216	52,701	120,476	97,742
Singapore
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6,367	7,887	12,065	15,267
FMS
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,295,453	1,163,579	2,538,032	2,296,049
FMS | U.S.
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,134,499	1,016,870	2,214,954	2,007,131
FMS | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	75,864	68,000	150,332	133,822
FMS | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	85,090	78,709	172,746	155,096
FMS | Mexico
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
FMS | Singapore
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 | U.S.
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	330,622	272,446	629,592	539,076
DTS | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0		0	0
DTS | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | Mexico
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
DTS | Singapore
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 | U.S.
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	484,194	363,466	875,849	721,812
SCS | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	47,747	41,650	90,841	82,496
SCS | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
SCS | Mexico
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	66,216	52,701	120,476	97,742
SCS | Singapore
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6,367	7,887	12,065	15,267
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(141,261)	(113,701)	(274,050)	(227,431)
Intersegment Eliminations | U.S.
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(135,569)	(109,071)	(263,285)	(218,653)
Intersegment Eliminations | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(5,692)	(4,630)	(10,765)	(8,778)
Intersegment Eliminations | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Intersegment Eliminations | Mexico
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Intersegment Eliminations | Singapore
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0