STOCK-BASED COMPENSATION: Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Sep. 30, 2020 USD ($) $ / shares shares
Stock Option Activity - Number of Shares
Outstanding at beginning of the period (in shares) | shares	1,350,658
Exercised (in shares) | shares	(154,165)
Forfeited or cancelled (in shares) | shares	(5,024)
Outstanding at end of the period (in shares) | shares	1,191,469
Weighted-average exercise price per share
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 14.43
Exercised (in dollars per share) | $ / shares	10.74
Forfeited or cancelled (in dollars per share) | $ / shares	1.72
Outstanding at the end of the period (in dollars per share) | $ / shares	$ 14.96
Weighted average remaining contractual term	2 years 10 months 24 days
Exercised | $	$ 6,025
Outstanding at the end of the period | $	$ 43,855
Exercisable at the end of the period (in shares) | shares	1,144,331
Exercisable at the end of the period (in dollars per share) | $ / shares	$ 15.50
Exercisable at the end of the period	2 years 8 months 12 days
Exercisable at the end of the period | $	$ 41,506