RESTRUCTURING COSTS - Restructuring Accrual (Details) - 2017 Strategic Restructuring Plan - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Liability beginning of period	$ 1,579,000
Charges	0	$ 0	$ (1,600,000)
Restructuring adjustment	(44,000)
Non-cash activity	(26,000)
Cash Payments	(1,468,000)
Liability end of period	41,000		1,579,000
Employee Separation Costs
Restructuring Reserve [Roll Forward]
Liability beginning of period	1,522,000
Charges	0
Restructuring adjustment	(44,000)
Non-cash activity	0
Cash Payments	(1,468,000)
Liability end of period	10,000		1,522,000
Asset-Related Charges
Restructuring Reserve [Roll Forward]
Liability beginning of period	0
Charges	0
Restructuring adjustment	0
Non-cash activity	0
Cash Payments	0
Liability end of period	0		0
Other
Restructuring Reserve [Roll Forward]
Liability beginning of period	57,000
Charges	0
Restructuring adjustment	0
Non-cash activity	(26,000)
Cash Payments
Liability end of period	$ 31,000		$ 57,000