RESTRUCTURING CHARGES - Summary of Changes in Restructuring Accrual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Restructuring Reserve - Beginning Balance	$ 366	$ 1,103	$ 3,605
Restructuring charges	0	412	3,662
Payments	(328)	(1,097)	(6,127)
Reserve adjustments	(30)	(52)	(37)
Restructuring Reserve - Ending Balance	8	366	1,103
Employee severance costs
Restructuring Reserve [Roll Forward]
Restructuring Reserve - Beginning Balance	128	0	2,005
Restructuring charges	0	506	2,413
Payments	(123)	(358)	(4,406)
Reserve adjustments	(5)	(20)	(12)
Restructuring Reserve - Ending Balance	0	128	0
Contract termination costs
Restructuring Reserve [Roll Forward]
Restructuring Reserve - Beginning Balance	238	1,103	1,600
Restructuring charges	0	(94)	825
Payments	(205)	(739)	(1,322)
Reserve adjustments	(25)	(32)	0
Restructuring Reserve - Ending Balance	8	238	1,103
Other costs
Restructuring Reserve [Roll Forward]
Restructuring Reserve - Beginning Balance	0	0	0
Restructuring charges	0	0	424
Payments	0	0	(399)
Reserve adjustments	0	0	(25)
Restructuring Reserve - Ending Balance	$ 0	$ 0	$ 0