INCOME TAXES - CURRENT INCOME TAX (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Components of (loss) income before income taxes
Domestic	$ 134,265	$ 136,239	$ 86,050
Foreign	98,520	386	(9,085)
Income before income taxes	232,785	136,625	76,965
Current:
U.S. federal	8,240	(7,327)	19,271
U.S. state and local	2,857	(1,266)	2,521
Foreign	22,274	4,208	(13,012)
Total current income taxes	33,371	(4,385)	8,780
Deferred:
U.S. federal	(128,317)	(13,530)	969
U.S. state and local	(9,157)	195	2,395
Foreign	3,051	(19,188)	(2,482)
Total deferred income taxes	(134,423)	(32,523)	882
(Benefit from) Provision for income taxes	$ (101,052)	$ (36,908)	$ 9,662
Reconciliation of effective tax rate to the U.S. statutory federal income tax rate
U.S. federal statutory rate	21.00%	31.60%	35.00%
State and local taxes, net of U.S. federal benefit	2.90%	0.50%	4.90%
Foreign tax rate differential(1)	(9.00%)	(6.90%)	(1.40%)
Foreign earnings	5.10%	1.20%	5.50%
Tax credits(2)	(15.00%)	(16.50%)	(45.80%)
Excess tax benefits from stock-based compensation(3)	(5.70%)	(38.90%)	0.00%
One-time transition tax(4)	(2.00%)	19.50%	0.00%
Domestic production deduction	0.00%	(2.80%)	(2.50%)
Valuation allowance—domestic(5)	(46.00%)	(0.50%)	10.10%
Valuation allowance—foreign	0.00%	(2.50%)	0.10%
Change in reserves	1.30%	(11.00%)	2.90%
Other(6)	4.00%	(0.70%)	3.70%
Effective tax rate	(43.40%)	(27.00%)	12.50%