ACQUISITIONS & DIVESTITURES - Summary of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Feb. 05, 2020	Apr. 03, 2019	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Estimated fair value of contingent purchase consideration			$ 1,748
Estimated fair value of assets acquired and liabilities assumed:
Goodwill			1,725,680	$ 1,715,485	$ 1,712,764
Gigavation
Business Acquisition [Line Items]
Initial cash payment	$ 7,200
Estimated fair value of contingent purchase consideration	800		700
Estimated purchase price	8,000
Estimated fair value of assets acquired and liabilities assumed:
Cash	7
Accounts receivable	209
Prepaid and other current assets	5
Intangible assets	4,760
Deferred tax liabilities	(693)
Accounts payable	(50)
Accrued other liabilities	(54)
Goodwill	$ 3,816
Eastwind
Business Acquisition [Line Items]
Initial cash payment		$ 4,154
Estimated fair value of contingent purchase consideration		1,000	$ 1,000
Estimated purchase price		5,154
Estimated fair value of assets acquired and liabilities assumed:
Property, plant and equipment		17
Intangible assets		4,230
Accrued other liabilities		(96)
Goodwill		$ 1,003