INCOME TAXES - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal statutory income tax rate (in hundredths)	35.00%
Income tax reconciliation [Abstract]
Tax at federal statutory rate	$ 3,796	$ (1,259)	$ (5,308)
State taxes, net	1,246	(1,285)	(1,289)
Non-deductible stock compensation	1,252	1,065	327
Foreign rate differential	1,078	1,567	3,245
Research credits	(741)	(548)	(930)
Change in valuation allowance	(6,050)	556	4,961
Other	152	140	155
Income tax provision	733	236	$ 1,161
Change in valuation amount	$ 0	$ 200