RESTRUCTURING CHARGES (Restructuring Reserve) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Reserve [Roll Forward]
Balance at December 31, 2015			$ 1,409
Restructuring	$ 182	$ 877	608	$ 877
Cash expenditures			(1,553)
Foreign currency translation adjustment			40
Balance at September 30, 2016	504		504
Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring	0		269
Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring	68		114
Other related costs
Restructuring Reserve [Roll Forward]
Restructuring	114		225
Operating segment | MMS
Restructuring Reserve [Roll Forward]
Balance at December 31, 2015			167
Restructuring	0		0
Cash expenditures			(14)
Foreign currency translation adjustment			0
Balance at September 30, 2016	153		153
Operating segment | MMS | Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring	0		0
Operating segment | MMS | Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring			0
Operating segment | MMS | Other related costs
Restructuring Reserve [Roll Forward]
Restructuring	0		0
Operating segment | ATA
Restructuring Reserve [Roll Forward]
Balance at December 31, 2015			1,242
Restructuring	182		608
Cash expenditures			(1,539)
Foreign currency translation adjustment			40
Balance at September 30, 2016	351		351
Operating segment | ATA | Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring	0		269
Operating segment | ATA | Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring	68		114
Operating segment | ATA | Other related costs
Restructuring Reserve [Roll Forward]
Restructuring	$ 114		$ 225