COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 13,902	$ 11,719	$ 41,499	$ 30,709
Income tax benefit	(2,798)	(1,624)	(5,941)	(7,605)
Total stock-based compensation, net of tax	11,104	10,095	35,558	23,104
Employee compensation and benefits	57,314		57,314		$ 68,882
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	1,019	1,067	2,994	3,103
Research, development, and engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	4,584	2,887	12,516	7,877
Selling, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	8,299	7,765	25,989	19,729
Stock-based compensation expense included in operating expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 12,883	$ 10,652	$ 38,505	$ 27,606
Share-based Payment Arrangement, Tranche One [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting percentage			75.00%
Share-based Payment Arrangement, Tranche Two [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting percentage			25.00%