GOODWILL AND INTANGIBLE ASSETS - Schedule of Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 32,661	$ 28,205
Product revenue
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	0	2
Cost of product revenue
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	9,191	9,814
Operating expense
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 23,470	$ 18,389