SEGMENT INFORMATION GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 363,403	$ 384,719	$ 428,904	$ 425,382	$ 376,034	$ 370,988	$ 364,399	$ 357,501	$ 1,602,408	$ 1,468,922	$ 1,265,497
Long-Lived Assets	384,872				421,248				384,872	421,248	437,201
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									711,887	642,743	558,278
Long-Lived Assets	137,410				151,841				137,410	151,841	171,587
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									469,322	411,570	354,117
Long-Lived Assets	165,827				176,923				165,827	176,923	156,505
Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									271,374	282,692	248,019
Long-Lived Assets	52,393				62,543				52,393	62,543	68,187
Other Countries [Domain]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									149,825	131,917	105,083
Long-Lived Assets	$ 29,242				$ 29,941				$ 29,242	$ 29,941	$ 40,922