Summary of Significant Accounting Policies, Deferred Compensation Plan (Details) - USD ($)	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Deferred Compensation Plan [Abstract]
Carrying value of plan assets	$ 2,202,000	$ 1,652,000
Deferred compensation obligation	2,202,000	1,652,000
Expense related to the deferred compensation plan	119,000	96,000	$ 79,000
Short-term investments redeemed for the payment of deferred compensation liabilities	0	46,000
Gain (Loss) on Equity Investments [Abstract]
Net gain recognized on equity securities	163,000	521,000	96,000
Less: net gain recognized on equity securities sold	0	10,000	193,000
Unrealized gain (loss) recognized on equity securities still held	$ 163,000	$ 511,000	$ (97,000)

Amount of short-term investments redeemed during the reporting period.

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- Definition

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

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- Definition

The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit.

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Amount of unrealized and realized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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Amount of realized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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Amount of unrealized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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