CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 159,338	$ 143,291	$ 116,920
Other comprehensive income (loss), net of tax:
Change in foreign currency translation adjustment	(9,261)	13,529	(24,801)
Available-for-sale investments:
Change in net unrealized gains (losses)	(592)	(854)	5,102
Less - reclassification adjustment for net gains realized and included in net income			(3,388)
Net change (net of tax effect of $351, $(113) and $113)	(592)	(854)	1,714
Cash flow hedges:
Change in unrealized gains (losses)	(8,630)	6,821	600
Less - reclassification adjustment for net gains (losses) realized and included in net income	4,781	(5,586)	(132)
Net change (net of tax effect of $370, $0 and 0)	(3,849)	1,235	468
Total other comprehensive income (loss)	(13,702)	13,910	(22,619)
Comprehensive income	$ 145,636	$ 157,201	$ 94,301

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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