Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 213,442	$ 147,065	$ 93,999
OTHER COMPREHENSIVE INCOME (LOSS):
Foreign Currency Transaction Gain (Loss), Unrealized	15,061	(19,081)	(54,457)
Net unrealized loss on foreign currency translation	15,061	(19,081)	(54,457)
Unrealized gain (loss) on interest rate swaps:
Unrealized gain (loss) arising during the period, net of tax benefit	1,034	1,728	(9,856)
Reclassification adjustment for loss included in interest expense, net of tax provision	7,623	8,393	8,313
Unrealized gain (loss) on interest rate risk management activities, net of tax	8,657	10,121	(1,543)
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAXES	23,718	(8,960)	(56,000)
COMPREHENSIVE INCOME	$ 237,160	$ 138,105	$ 37,999