Statements of Shareholders' Equity (Unaudited) - USD ($)
Cumulative Effect, Period of Adoption, Adjustment [Member]
Common Stock [Member]
Common Stock [Member]
Additional Paid-in Capital [Member]
AOCI Attributable to Parent [Member]
Retained Earnings [Member]
Total
Balance (in shares) at Mar. 31, 2020   4,835,038        
Balance at Mar. 31, 2020   $ 48,350 $ 19,383,956 $ 516,523 $ 58,046,520 $ 77,995,349
Unrealized gain (loss) on marketable securities, net of tax   1,242,662 1,242,662
Net income   2,411,865 2,411,865
Total comprehensive income   3,654,527
Stock-based compensation   2,707 2,707
Cash dividends declared ($1.00 per share of common stock)   (4,835,038) (4,835,038)
Balance (in shares) at Jun. 30, 2020 4,835,038          
Balance at Jun. 30, 2020   $ 48,350 19,386,663 1,759,185 55,623,347 76,817,545
Balance (in shares) at Mar. 31, 2021   4,833,232        
Balance at Mar. 31, 2021   $ 48,332 19,338,127 1,101,119 50,404,364 70,891,942 [1]
Unrealized gain (loss) on marketable securities, net of tax   (90,165) (90,165)
Net income   3,579,566 3,579,566
Total comprehensive income   3,489,401
Stock-based compensation   7,238 7,238
Cash dividends declared ($1.00 per share of common stock)   (4,833,232) (4,833,232)
Balance (in shares) at Jun. 30, 2021 4,833,232          
Balance at Jun. 30, 2021   $ 48,332 $ 19,345,365 $ 1,010,954 $ 49,150,698 $ 69,555,349
[1] The March 31, 2021 Balance Sheet is derived from the audited financial statements contained in our Annual Report on Form 10-K for the fiscal year ended March 31, 2021.