GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,187,117	$ 1,170,562
Accumulated Amortization	(317,743)	(257,893)
Net	869,374	912,669
Developed technology
Finite-Lived Intangible Assets [Line Items]
Cost	258,729	254,005
Accumulated Amortization	(129,824)	(110,200)
Net	128,905	143,805
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	841,876	831,731
Accumulated Amortization	(139,317)	(105,319)
Net	702,559	726,412
Distributor relationships and technology licenses
Finite-Lived Intangible Assets [Line Items]
Cost	8,961	8,290
Accumulated Amortization	(4,283)	(3,068)
Net	4,678	5,222
Definite-lived trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Cost	44,230	43,817
Accumulated Amortization	(15,364)	(12,078)
Net	28,866	31,739
Core technology
Finite-Lived Intangible Assets [Line Items]
Cost	7,280	7,108
Accumulated Amortization	(6,414)	(6,009)
Net	866	1,099
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	306	278
Accumulated Amortization	(306)	(278)
Net	0	0
Leasehold interest
Finite-Lived Intangible Assets [Line Items]
Cost	2,600	2,600
Accumulated Amortization	(1,484)	(998)
Net	1,116	1,602
Backlog
Finite-Lived Intangible Assets [Line Items]
Cost	18,434	18,142
Accumulated Amortization	(18,429)	(18,133)
Net	5	9
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Cost	3,157	3,047
Accumulated Amortization	(1,094)	(594)
Net	2,063	2,453
Other
Finite-Lived Intangible Assets [Line Items]
Cost	1,208	1,208
Accumulated Amortization	(892)	(880)
Net	$ 316	$ 328