STOCK-BASED COMPENSATION: - Stock-based Compensation Expense Related to Discontinued Operations (Details) $ in Millions	6 Months Ended
	Sep. 30, 2020 USD ($) numberOfExerciseMultiple
Consideration Holdback
Share-based compensation
Contingent consideration arrangements, number of annual increments | numberOfExerciseMultiple	3
Data Plus Math Corporation
Share-based compensation
Holdback consideration transferred	$ 24.4
Holdback expenses	10.2
Data Plus Math Corporation | Accrued Liabilities
Share-based compensation
Holdback expenses	$ 2.0