GOODWILL AND INTANGIBLE ASSETS - Schedule of Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 28,434	$ 31,262	$ 56,639	$ 62,438
Product revenue
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	2	2,869	4	5,746
Cost of product revenue
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	10,129	10,757	19,943	21,429
Operating expense
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 18,303	$ 17,636	$ 36,692	$ 35,263