FAIR VALUE OF FINANCIAL INSTRUMENTS: (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Fair value of assets and liabilities
Assets of non-qualified retirement plan	$ 11,704	$ 15,528
Fair value measurements on recurring basis | Estimate of Fair Value Measurement
Fair value of assets and liabilities
Assets of non-qualified retirement plan	11,704	15,528
Total assets	11,704	15,528
Fair value measurements on recurring basis | Estimate of Fair Value Measurement | Level 1
Fair value of assets and liabilities
Assets of non-qualified retirement plan	11,704	15,528
Total assets	11,704	15,528
Fair value measurements on recurring basis | Estimate of Fair Value Measurement | Level 2
Fair value of assets and liabilities
Assets of non-qualified retirement plan	0	0
Total assets	0	0
Fair value measurements on recurring basis | Estimate of Fair Value Measurement | Level 3
Fair value of assets and liabilities
Assets of non-qualified retirement plan	0	0
Total assets	$ 0	$ 0