ENTITY WIDE DISCLOSURES - Geographic Breakdown of Revenues and Total Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 286,554	$ 250,854
Total assets	1,113,918		$ 1,147,418
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	215,212	202,053
Total assets	776,238		788,780
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	27,248	21,985
Total assets	59,258		66,056
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	25,999	16,889
Total assets	227,621		234,847
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	18,095	$ 9,927
Total assets	$ 50,801		$ 57,735