ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (INCOME STATEMENT CLASSIFICATION TABLE) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Presentation of Income Statement Reclassifications [Line Items]
Sales Revenue Services Net	$ 349,853	$ 353,429	$ 725,102	$ 691,706
Interest Expense.	7,765	2,912	14,224	5,230
Benefit from (provision for) income taxes	(653)	(1,597)	(2,755)	(6,988)
Net income	$ 6,297	$ 15,794	12,229	35,961
Accumulated Other Comprehensive Income (Loss)
Presentation of Income Statement Reclassifications [Line Items]
Net Income (Loss) - Other			7,659	7,340
Derivative Valuation, Net of Tax
Presentation of Income Statement Reclassifications [Line Items]
Net Income (Loss) - Other			$ 7,458	$ 7,105