Summary of Significant Accounting Policies, Deferred Compensation Plan (Details) - USD ($)	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Deferred Compensation Plan [Abstract]
Carrying value of plan assets	$ 2,011,000	$ 2,202,000
Deferred compensation obligation	2,011,000	2,202,000
Expense related to the deferred compensation plan	75,000	119,000	$ 96,000
Short-term investments redeemed for the payment of deferred compensation liabilities	297,000	0
Gain (Loss) on Equity Investments [Abstract]
Net (loss) gain recognized on equity securities	(181,000)	163,000	521,000
Less: net (loss) gain recognized on equity securities sold	(15,000)	0	10,000
Unrealized (loss) gain recognized on equity securities still held	$ (166,000)	$ 163,000	$ 511,000