Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 259,016	$ 112,170	$ 52,116
Other comprehensive (loss) income:
Foreign currency translation (loss) gain	(11,431)	16,862	(5,855)
Net unrealized gain (loss) on marketable securities	946	(460)	(211)
Other comprehensive (loss) income	(10,485)	16,402	(6,066)
Comprehensive income	$ 248,531	$ 128,572	$ 46,050

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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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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