RESTRUCTURING CHARGES (Cost Incurred and Expected to be Incurred) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	$ 4,325		$ 4,325
Restructuring	182	$ 877	608	$ 877
Cumulative Costs Incurred to Date	4,166		4,166
Employee termination costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	3,583		3,583
Restructuring	0		269
Cumulative Costs Incurred to Date	3,569		3,569
Facility exit costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	137		137
Restructuring	68		114
Cumulative Costs Incurred to Date	114		114
Other related costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	605		605
Restructuring	114		225
Cumulative Costs Incurred to Date	483		483
Operating segment | MMS
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	260		260
Restructuring	0		0
Cumulative Costs Incurred to Date	255		255
Operating segment | MMS | Employee termination costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	260		260
Restructuring	0		0
Cumulative Costs Incurred to Date	255		255
Operating segment | MMS | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring			0
Operating segment | MMS | Other related costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	0		0
Restructuring	0		0
Cumulative Costs Incurred to Date	0		0
Operating segment | ATA
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	4,065		4,065
Restructuring	182		608
Cumulative Costs Incurred to Date	3,911		3,911
Operating segment | ATA | Employee termination costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	3,323		3,323
Restructuring	0		269
Cumulative Costs Incurred to Date	3,314		3,314
Operating segment | ATA | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	137		137
Restructuring	68		114
Cumulative Costs Incurred to Date	114		114
Operating segment | ATA | Other related costs
Restructuring Cost and Reserve [Line Items]
Total Costs Expected to be Incurred	605		605
Restructuring	114		225
Cumulative Costs Incurred to Date	$ 483		$ 483