CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Mar. 31, 2020	$ 225	$ 64,649	$ 81,870	$ 2,099	$ 148,843
Balance (in shares) at Mar. 31, 2020	22,544,285
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			3,023		3,023
Cash dividend on common stock			(2,227)		(2,227)
Exercise of stock options		9			$ 9
Exercise of stock options (in shares)	5,000				5,000
Stock repurchased	$ (3)	(1,444)			$ (1,447)
Stock repurchased (in shares)	(295,900)
Restricted stock grants (in shares)	90,763
Restricted stock cancelled (in shares)	(7,913)
Stock-based compensation expense		206			206
Other comprehensive income (loss), net				639	639
Balance at Sep. 30, 2020	$ 222	63,420	82,666	2,738	149,046
Balance (in shares) at Sep. 30, 2020	22,336,235
Balance at Jun. 30, 2020	$ 222	63,254	81,240	2,762	147,478
Balance (in shares) at Jun. 30, 2020	22,245,472
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			2,543		2,543
Cash dividend on common stock			(1,117)		(1,117)
Restricted stock grants (in shares)	90,763
Stock-based compensation expense		166			166
Other comprehensive income (loss), net				(24)	(24)
Balance at Sep. 30, 2020	$ 222	63,420	82,666	2,738	149,046
Balance (in shares) at Sep. 30, 2020	22,336,235
Balance at Mar. 31, 2021	$ 223	63,650	87,881	(160)	151,594
Balance (in shares) at Mar. 31, 2021	22,351,235
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			12,185		12,185
Cash dividend on common stock			(2,338)		(2,338)
Exercise of stock options		17	(1)		$ 16
Exercise of stock options (in shares)	6,000				6,000
Stock repurchased	$ (2)	(1,722)			$ (1,724)
Stock repurchased (in shares)	(249,908)
Restricted stock grants (in shares)	57,380
Stock-based compensation expense		177			177
Other comprehensive income (loss), net				(150)	(150)
Balance at Sep. 30, 2021	$ 221	62,122	97,727	(310)	159,760
Balance (in shares) at Sep. 30, 2021	22,164,707
Balance at Jun. 30, 2021	$ 222	63,213	92,522	1,019	156,976
Balance (in shares) at Jun. 30, 2021	22,277,868
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			6,430		6,430
Cash dividend on common stock			(1,224)		(1,224)
Exercise of stock options		17	(1)		16
Exercise of stock options (in shares)	6,000
Stock repurchased	$ (1)	(1,230)			(1,231)
Stock repurchased (in shares)	(176,541)
Restricted stock grants (in shares)	57,380
Stock-based compensation expense		122			122
Other comprehensive income (loss), net				(1,329)	(1,329)
Balance at Sep. 30, 2021	$ 221	$ 62,122	$ 97,727	$ (310)	$ 159,760
Balance (in shares) at Sep. 30, 2021	22,164,707