OTHER ACCRUED EXPENSES: (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Business Acquisition [Line Items]
Liabilities of non-qualified retirement plan	$ 17,532	$ 15,838
Short-term lease liabilities (see Note 4)	7,158	9,608
Other miscellaneous accrued expenses	12,639	23,852
Other accrued expenses	56,221	58,353
Rakam Technology Asset Acquisition
Business Acquisition [Line Items]
Rakam consideration holdback (see Note 5)	223	0
Pacific Data Partners LLC
Business Acquisition [Line Items]
Business combination, contingent consideration, liability, current	6,058	0
Other accrued expenses	6,100
Data Plus Math Corporation
Business Acquisition [Line Items]
Business combination, contingent consideration, liability, current	4,061	6,092
Acuity Data
Business Acquisition [Line Items]
Business combination, contingent consideration, liability, current	2,066	2,208
DataFleets, Ltd
Business Acquisition [Line Items]
Business combination, contingent consideration, liability, current	5,284	755
Diablo.AI, Inc.
Business Acquisition [Line Items]
Business combination, contingent consideration, liability, current	$ 1,200	$ 0