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)		23
Exercise of stock options	16	$ 16
Exercise of stock options (in shares)		12
Cancellation of restricted stock awards (in shares)		(22)
Share-based compensation	41	$ 41
Net income (loss)	1,097			1,097
Balance at Dec. 31, 2018	109,591	$ 34,621	(70,459)	145,429
Balance (in shares) at Dec. 31, 2018		7,908
Balance at Sep. 30, 2018	110,464	$ 34,589	(70,459)	146,334
Balance (in shares) at Sep. 30, 2018		7,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards (in shares)		6
Exercise of stock options	5	$ 5
Exercise of stock options (in shares)		1
Cancellation of restricted stock awards (in shares)		(3)
Share-based compensation	27	$ 27
Net income (loss)	(905)			(905)
Balance at Dec. 31, 2018	109,591	$ 34,621	(70,459)	145,429
Balance (in shares) at Dec. 31, 2018		7,908
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)		39
Exercise of stock options	5	$ 5
Exercise of stock options (in shares)		2
Cancellation of restricted stock awards (in shares)		(25)
Share-based compensation	148	$ 148
Treasury stock repurchases	(216)		(216)
Net income (loss)	1,170			1,170
Balance at Dec. 31, 2019	105,992	$ 34,813	(70,675)	141,854
Balance (in shares) at Dec. 31, 2019		7,926
Balance at Sep. 30, 2019	105,833	$ 34,749	(70,459)	141,543
Balance (in shares) at Sep. 30, 2019		7,925
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	5	$ 5
Exercise of stock options (in shares)		1
Share-based compensation	59	$ 59
Treasury stock repurchases	(216)		(216)
Net income (loss)	311			311
Balance at Dec. 31, 2019	$ 105,992	$ 34,813	$ (70,675)	$ 141,854
Balance (in shares) at Dec. 31, 2019		7,926