STOCKHOLDERS' EQUITY: - Stock-based Compensation Expense Related to Discontinued Operations (Details) $ in Millions	12 Months Ended
	Mar. 31, 2021 USD ($) numberOfExerciseMultiple	Mar. 31, 2020 USD ($) numberOfExerciseMultiple	Mar. 31, 2019 USD ($)	Feb. 17, 2021 numberOfExerciseMultiple	Jul. 02, 2019 numberOfExerciseMultiple
Share-based compensation
Stock-based compensation of discontinued operations			$ 62.9
Consideration Holdback
Share-based compensation
Contingent consideration arrangements, number of annual increments | numberOfExerciseMultiple		3
DataFleets, Ltd
Share-based compensation
Holdback consideration transferred	$ 18.1
Holdback expenses	0.8
DataFleets, Ltd | Accrued Liabilities
Share-based compensation
Holdback expenses	$ 0.8
DataFleets, Ltd | Consideration Holdback
Share-based compensation
Contingent consideration arrangements, number of annual increments | numberOfExerciseMultiple	3			3
Data Plus Math Corporation
Share-based compensation
Holdback consideration transferred		$ 24.4
Holdback expenses		14.2
Data Plus Math Corporation | Accrued Liabilities
Share-based compensation
Holdback expenses		$ 6.1
Data Plus Math Corporation | Consideration Holdback
Share-based compensation
Contingent consideration arrangements, number of annual increments | numberOfExerciseMultiple					3