STOCKHOLDERS' EQUITY: Qualified Employee Stock Purchase Plan (Details) - Employee Stock - USD ($) $ in Millions	12 Months Ended			36 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2021
Share-based compensation
Shares which remained available for future grants (in shares)	400,000			400,000
Shares subject to purchase in the current purchase period (in shares)	100,000
Stock issued during period, ESPP (in shares)				200,683
Share-based compensation expense	$ 1.0	$ 0.5	$ 0.4