ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (INCOME STATEMENT CLASSIFICATION TABLE) (DETAILS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Presentation of Income Statement Reclassifications [Line Items]
Sales Revenue Services Net	$ 305,105	$ 310,223	$ 617,515	$ 635,744
Interest Expense.	1,753	1,676	3,717	3,374
Benefit from (provision for) income taxes	(2,952)	(7,841)	(7,480)	(12,246)
Net income	12,542	15,493	24,447	35,528
Accumulated Other Comprehensive Income (Loss)
Presentation of Income Statement Reclassifications [Line Items]
Net Income (Loss) - Other			7,414	(2,895)
Derivative Valuation, Net of Tax
Presentation of Income Statement Reclassifications [Line Items]
Net Income (Loss) - Other			7,010	(2,441)
Reclassification from accumulated other comprehensive income
Presentation of Income Statement Reclassifications [Line Items]
Net income	(3,457)	(1,301)
Net Income (Loss) - Other	(202)	(208)	(404)	(454)
Reclassification from accumulated other comprehensive income | Derivative Valuation, Net of Tax
Presentation of Income Statement Reclassifications [Line Items]
Net income			(7,010)	(2,441)
Reclassification from accumulated other comprehensive income | Tax effect
Presentation of Income Statement Reclassifications [Line Items]
Benefit from (provision for) income taxes	2,505	1,467	5,078	2,291
Provision for income taxes - Other	22	22	44	50
Reclassification from accumulated other comprehensive income | Cost of Services
Presentation of Income Statement Reclassifications [Line Items]
Cost of services	(224)	(230)	(448)	(504)
Foreign Exchange Forward | Reclassification from accumulated other comprehensive income | Foreign Currency Translation Adjustment
Presentation of Income Statement Reclassifications [Line Items]
Sales Revenue Services Net	(5,860)	(2,506)	(11,757)	(4,213)
Interest Rate | Reclassification from accumulated other comprehensive income | Loss on interest rate swaps [Member]
Presentation of Income Statement Reclassifications [Line Items]
Interest Expense.	$ (102)	$ (262)	$ (331)	$ (519)