Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 107,583	$ 63,911	$ 204,358	$ 195,246
Other comprehensive (loss) income:
Foreign currency translation adjustments	(7,771)	7,689	(26,046)	31,184
Change in unrealized gain (loss) on investments, net of income tax (provision) benefit of $(494), $(187), $78 and $(868) for the three and nine months ended September 30, 2018 and 2017, respectively	1,524	310	(242)	1,438
Other comprehensive (loss) income	(6,247)	7,999	(26,288)	32,622
Comprehensive income	$ 101,336	$ 71,910	$ 178,070	$ 227,868

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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