CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 163,642	$ 179,948	$ 281,737	$ 277,007
Other comprehensive income (loss):
Foreign currency translation adjustment	18,172	(16,331)	(3,192)	(40,666)
Cash flow hedges:
Change in unrealized gains	(3,728)	2,350	2,297	4,219
Reclassification to earnings	2,184	0	(1,157)	0
Tax effect on effective cash flow hedges	(386)	58	301	167
Change in fair value of effective cash flow hedge	(1,930)	2,408	1,441	4,386
Change in fair value of available for sale securities	(267)	168	453	1,058
Other comprehensive (loss) income	15,975	(13,755)	(1,298)	(35,222)
Comprehensive income	$ 179,617	$ 166,193	$ 280,439	$ 241,785