ENTITY WIDE DISCLOSURES - Geographic Breakdown of Revenues and Total Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 336,440	$ 235,399	$ 587,294	$ 427,806
Total assets	1,223,024		1,223,024		$ 798,991
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	241,064	168,519	443,117	317,483
Total assets	995,136		995,136		682,124
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	41,836	39,241	63,821	62,943
Total assets	61,350		61,350		59,626
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	33,152	13,287	50,041	25,358
Total assets	115,468		115,468		33,271
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	20,388	$ 14,352	30,315	$ 22,022
Total assets	$ 51,070		$ 51,070		$ 23,970