GOODWILL AND OTHER INTANGIBLE ASSETS, Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2020
Other Intangible Assets [Abstract]
Gross carrying amount	$ 87,888	$ 73,391
Accumulated amortization	(49,274)	(38,927)
Intangible Assets, Net Carrying Amount	38,614	34,464
Future amortization expense [Abstract]
Intangible Assets, Net Carrying Amount	38,614	34,464
Systems Management Planning (SMP) [Member]
Other Intangible Assets [Abstract]
Intangibles assets acquired				$ 14,280
Customer Relationships & Other Intangibles [Member]
Other Intangible Assets [Abstract]
Gross carrying amount	77,335	63,006
Accumulated amortization	(42,115)	(33,000)
Intangible Assets, Net Carrying Amount	35,220	30,006
Total amortization expense	10,300	9,400	$ 7,900
Future amortization expense [Abstract]
Year ending March 31, 2022	10,073
2023	8,028
2024	6,218
2025	4,647
2026 and thereafter	6,254
Intangible Assets, Net Carrying Amount	35,220	30,006
Customer Relationships & Other Intangibles [Member] | Systems Management Planning (SMP) [Member]
Other Intangible Assets [Abstract]
Intangibles assets acquired	$ 14,300
Customer Relationships & Other Intangibles [Member] | Minimum [Member]
Other Intangible Assets [Abstract]
Estimated useful life	5 years
Customer Relationships & Other Intangibles [Member] | Maximum [Member]
Other Intangible Assets [Abstract]
Estimated useful life	10 years
Capitalized Software Development [Member]
Other Intangible Assets [Abstract]
Gross carrying amount	$ 10,553	10,385
Accumulated amortization	(7,159)	(5,927)
Intangible Assets, Net Carrying Amount	$ 3,394	4,458
Estimated useful life	5 years
Future amortization expense [Abstract]
Intangible Assets, Net Carrying Amount	$ 3,394	$ 4,458