DISCONTINUED OPERATIONS: Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Incremental increase to previous periods	$ 15.5
Acxiom Marketing Solutions | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from disposal of operations		$ 2,300.0
Closing adjustments and transaction costs		49.0
Repayments of debt		230.5
Discontinued operation, gain (loss) on disposal of discontinued operation, net of tax		$ 1,700.0