EMPLOYEE BENEFIT PLANS - Trust Company Stock Options (Details) - USD ($)	12 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised (in shares)	1,511	6,000	20,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	0	0	0
Trust Company \| President and Chief Executive Officer \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options outstanding	0	0
Stock Option Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0	$ 0	$ 0
Stock Option Plans \| Trust Company \| President and Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised (in shares)	0	500	500
Stock options granted (in shares)	0	0	0
Stock-based compensation expense			$ 44,000

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Gross number of share options (or share units) granted during the period.

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Number of non-vested options outstanding.

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Number of share options (or share units) exercised during the current period.

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