CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling interest
Beginning balance (in shares) at Mar. 31, 2020		135,927		(22,421)
Beginning balance at Mar. 31, 2020	$ 2,539,244	$ 1,359	$ 2,134,748	$ (820,572)	$ 1,282,085	$ (58,376)
Increase (Decrease) in Stockholders' Equity
Net income	88,505				88,505
Change in cumulative foreign currency translation adjustment	4,701					4,701
Change in gains on cash flow hedge, net	(4,305)					(4,305)
Change in fair value of available for sale securities	5,849					5,849
Stock-based compensation	49,037		49,037
Issuance of restricted stock, net of forfeitures and cancellations (in shares)		979
Issuance of restricted stock, net of forfeitures and cancellations	0	$ 10	(10)
Net share settlement of restricted stock awards (in shares)		(282)
Net share settlement of restricted stock awards	(38,506)	$ (3)	(38,503)
Employee share purchase plan settlement (in shares)		65
Employee share purchase plan settlement	6,503	$ 1	6,502
Ending balance (in shares) at Jun. 30, 2020		136,689		(22,421)
Ending balance at Jun. 30, 2020	2,651,028	$ 1,367	2,151,774	$ (820,572)	1,370,590	(52,131)
Beginning balance (in shares) at Mar. 31, 2021		137,584		(22,421)
Beginning balance at Mar. 31, 2021	3,331,892	$ 1,376	2,288,781	$ (820,572)	1,870,971	(8,664)	$ 0
Increase (Decrease) in Stockholders' Equity
Net income	152,256				152,256
Change in cumulative foreign currency translation adjustment	6,132					6,132
Change in fair value of available for sale securities	(238)					(238)
Stock-based compensation	73,767		73,767
Issuance of restricted stock, net of forfeitures and cancellations (in shares)		943
Issuance of restricted stock, net of forfeitures and cancellations	0	$ 9	(9)
Net share settlement of restricted stock awards (in shares)		(266)
Net share settlement of restricted stock awards	(48,261)	$ (2)	(48,259)
Employee share purchase plan settlement (in shares)		70
Employee share purchase plan settlement	9,230	$ 1	9,229
Issuance of shares related to Nordeus acquisition (in shares)		515
Issuance of shares related to Nordeus acquisition	94,154	$ 5	94,149
Call option related to Nordeus Acquisition	12,375						12,375
Ending balance (in shares) at Jun. 30, 2021		138,846		(22,421)
Ending balance at Jun. 30, 2021	$ 3,631,307	$ 1,389	$ 2,417,658	$ (820,572)	$ 2,023,227	$ (2,770)	$ 12,375