STOCK-BASED COMPENSATION: - Summary of Options (Details)	6 Months Ended
	Sep. 30, 2020 $ / shares shares
Stock options outstanding and exercisable by exercise price range
Options outstanding (in shares) | shares	1,191,469
Options outstanding - Weighted-average remaining contractual life	2 years 10 months 24 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 14.96
Options exercisable (in shares) | shares	1,144,331
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 15.50
Range of exercise price per share from $0.61 to $9.99
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	0.61
Exercise price per share, high end of range (in dollars per share)	$ 9.99
Options outstanding (in shares) | shares	148,147
Options outstanding - Weighted-average remaining contractual life	5 years 1 month 6 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 1.50
Options exercisable (in shares) | shares	101,009
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 1.30
Range of exercise price per share from $10.00 to $19.99
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	10.00
Exercise price per share, high end of range (in dollars per share)	$ 19.99
Options outstanding (in shares) | shares	691,732
Options outstanding - Weighted-average remaining contractual life	2 years
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 14.62
Options exercisable (in shares) | shares	691,732
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 14.62
Range of exercise price per share from $20.00 to $24.99
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	20.00
Exercise price per share, high end of range (in dollars per share)	$ 24.99
Options outstanding (in shares) | shares	351,590
Options outstanding - Weighted-average remaining contractual life	3 years 7 months 6 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 21.31
Options exercisable (in shares) | shares	351,590
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 21.31