FIXED ASSETS - Schedule of Fixed Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 258,788	$ 251,615
Less – accumulated depreciation	(210,314)	(193,900)
Fixed assets, net	48,474	57,715
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 9,742	9,561
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Computer equipment and internal use software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Fixed assets, gross	$ 177,098	170,518
Computer equipment and internal use software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Computer equipment and internal use software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 53,980	51,910
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	12 years
Demonstration and spare part units
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 17,968	$ 19,626
Demonstration and spare part units | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Demonstration and spare part units | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years