COMMITMENTS AND CONTINGENCIES - Summary of Changes in Product Warranty Accrual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	$ 2,803	$ 1,786	$ 1,691
Warranties issued in the period	3,021	2,783	2,031
Costs to service warranties	(3,974)	(3,059)	(1,981)
Warranty accrual adjustments	1,190	1,293	45
Ending balance	$ 3,040	$ 2,803	$ 1,786