Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Retained Earnings
Balance at Mar. 31, 2018	$ 108,437	$ 34,564	$ (70,459)	$ 144,332
Balance (in shares) at Mar. 31, 2018		7,895
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards (in shares)		18
Exercise of stock options	11	$ 11
Exercise of stock options (in shares)		11
Cancellation of restricted stock awards (in shares)		(20)
Share-based compensation	16	$ 16
Net income	2,000			2,000
Balance at Sep. 30, 2018	110,464	$ 34,591	(70,459)	146,332
Balance (in shares) at Sep. 30, 2018		7,904
Balance at Jun. 30, 2018	109,986	$ 34,695	(70,459)	145,750
Balance (in shares) at Jun. 30, 2018		7,909
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards (in shares)		15
Forfeiture of stock options	(59)	$ (59)
Cancellation of restricted stock awards	(45)	$ (45)
Cancellation of restricted stock awards (in shares)		(20)
Net income	582			582
Balance at Sep. 30, 2018	110,464	$ 34,591	(70,459)	146,332
Balance (in shares) at Sep. 30, 2018		7,904
Balance at Mar. 31, 2019	104,885	$ 34,660	(70,459)	140,684
Balance (in shares) at Mar. 31, 2019		7,910
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards (in shares)		40
Cancellation of restricted stock awards (in shares)		(25)
Share-based compensation	89	$ 89
Net income	859			859
Balance at Sep. 30, 2019	105,833	$ 34,749	(70,459)	141,543
Balance (in shares) at Sep. 30, 2019		7,925
Balance at Jun. 30, 2019	105,510	$ 34,694	(70,459)	141,275
Balance (in shares) at Jun. 30, 2019		7,928
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards (in shares)		21
Cancellation of restricted stock awards (in shares)		(24)
Share-based compensation	55	$ 55
Net income	268			268
Balance at Sep. 30, 2019	$ 105,833	$ 34,749	$ (70,459)	$ 141,543
Balance (in shares) at Sep. 30, 2019		7,925