CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 25,367	$ (2,736)	$ 97,060	$ 57,540	[1]
Other comprehensive income (loss):
Foreign currency translation adjustment	2,482	14,297	(24,335)	23,776
Cash flow hedges:
Change in unrealized gains (losses)	878	(5,217)	1,869	(5,217)
Tax effect on effective cash flow hedges	(24)	0	109	0
Change in fair value of effective cash flow hedge	854	(5,217)	1,978	(5,217)
Unrealized loss, net on available-for-sale securities, net of taxes	481	27	890	111
Change in fair value of available for sale securities	481	27	890	111
Other comprehensive income (loss)	3,817	9,107	(21,467)	18,670
Comprehensive income	$ 29,184	$ 6,371	$ 75,593	$ 76,210

[1] Prior period amounts have been adjusted retrospectively to reflect the adoption of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. Refer to Note 1 for further discussion.