IMPAIRMENT LOSSES AND RESTRUCTURING CHARGES (Summary of Activity, Restructuring Plans) (Details) - USD ($) $ in Thousands	6 Months Ended	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Beginning balance	$ 1,868	$ 1,868
Restructuring liability acquired as part of the Aegis Transactions		729
Accruals		3,479
Payments		(3,048)
Ending balance		3,028
Employee-related
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Restructuring liability acquired as part of the Aegis Transactions		400
Accruals	1,948	1,948
Payments		(1,588)
Ending balance		760
Facilities-related
Restructuring Reserve [Roll Forward]
Beginning balance	1,868	1,868
Restructuring liability acquired as part of the Aegis Transactions		329
Accruals	$ 1,531	1,531
Payments		(1,460)
Ending balance		$ 2,268