RESTRUCUTRING CHARGES (Restructuring Reserve) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Reserve [Roll Forward]
Balance at December 31, 2014	$ 1,409	$ 0
Restructuring charges	661	3,558	$ 0
Cash expenditures	(1,737)	(2,121)
Other adjustments to accrual	15	(8)
Foreign currency translation adjustment	38	(20)
Balance at September 30, 2015	386	1,409	0
Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring charges	269	3,300
Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring charges	134	0
Other related costs
Restructuring Reserve [Roll Forward]
Restructuring charges	258	258
Operating segment | MMS
Restructuring Reserve [Roll Forward]
Balance at December 31, 2014	167	0
Restructuring charges	0	255
Cash expenditures	(43)	(85)
Other adjustments to accrual	8	(3)
Foreign currency translation adjustment	0	0
Balance at September 30, 2015	132	167	0
Operating segment | MMS | Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring charges	0	255
Operating segment | MMS | Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring charges	0
Operating segment | MMS | Other related costs
Restructuring Reserve [Roll Forward]
Restructuring charges	0	0
Operating segment | ATA
Restructuring Reserve [Roll Forward]
Balance at December 31, 2014	1,242	0
Restructuring charges	661	3,303
Cash expenditures	(1,694)	(2,036)
Other adjustments to accrual	7	(5)
Foreign currency translation adjustment	38	(20)
Balance at September 30, 2015	254	1,242	$ 0
Operating segment | ATA | Employee termination costs
Restructuring Reserve [Roll Forward]
Restructuring charges	269	3,045
Operating segment | ATA | Facility exit costs
Restructuring Reserve [Roll Forward]
Restructuring charges	134	0
Operating segment | ATA | Other related costs
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 258	$ 258