RESTRUCTURINGS - 2015 RESTRUCTURING (Details)		12 Months Ended
	Mar. 03, 2015 USD ($) position	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)
Outstanding Restructuring Liability
Restructuring charges		$ 1,306,000	$ 1,462,000
Accrual balance at the end of the period		52,000
March 2015 Restructuring
Restructuring
Number of positions before restructuring | position	39
Number of positions after restructuring | position	21
Original exercise period for vested outstanding awards after termination	90 days
Modified exercise period for vested outstanding awards after termination	1 year
Expected cash payments	$ 999,000
Outstanding Restructuring Liability
Restructuring charges		1,395,000
Cash payments		(947,000)
Non-cash stock-based compensation expense		(307,000)
Adjustments or non-cash credits		(89,000)
Accrual balance at the end of the period		$ 52,000