GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,094,588	$ 1,192,226
Accumulated Amortization	(392,239)	(379,452)
Net	702,349	812,774
Developed technology
Finite-Lived Intangible Assets [Line Items]
Cost	243,093	259,758
Accumulated Amortization	(153,856)	(148,937)
Net	89,237	110,821
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	775,868	845,490
Accumulated Amortization	(188,347)	(176,425)
Net	587,521	669,065
Distributor relationships and technology licenses
Finite-Lived Intangible Assets [Line Items]
Cost	6,931	9,019
Accumulated Amortization	(4,571)	(5,389)
Net	2,360	3,630
Definite-lived trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Cost	39,430	44,387
Accumulated Amortization	(18,016)	(18,138)
Net	21,414	26,249
Core technology
Finite-Lived Intangible Assets [Line Items]
Cost	7,252	7,345
Accumulated Amortization	(6,761)	(6,712)
Net	491	633
Net beneficial leases
Finite-Lived Intangible Assets [Line Items]
Cost	336	336
Accumulated Amortization	(336)	(336)
Net	0	0
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Cost	301	317
Accumulated Amortization	(301)	(317)
Net	0	0
Leasehold interest
Finite-Lived Intangible Assets [Line Items]
Cost	500	2,600
Accumulated Amortization	(500)	(2,130)
Net	0	470
Backlog
Finite-Lived Intangible Assets [Line Items]
Cost	16,486	18,544
Accumulated Amortization	(16,486)	(18,544)
Net	0	0
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Cost	3,183	3,183
Accumulated Amortization	(2,152)	(1,621)
Net	1,031	1,562
Other
Finite-Lived Intangible Assets [Line Items]
Cost	1,208	1,247
Accumulated Amortization	(913)	(903)
Net	$ 295	$ 344