Condensed Consolidated Statements of Shareholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Treasury Shares	Capital in excess of stated value	Retained earnings	Accumulated other comprehensive loss
Beginning balance at Mar. 31, 2018	$ 108,431	$ 9,482	$ (2,486)	$ (1,911)	$ 103,601	$ (255)
Beginning balance (in shares) at Mar. 31, 2018		31,607	(8,283)
Cumulative effect of change in accounting policy	2,614				2,614
Share-based compensation	2,868			2,868
Restricted shares issued, net			$ 52	(52)
Restricted shares issued, net (in shares)			175
Shares issued upon exercise of SSARs			$ 16	(16)
Shares issued upon exercise of SSARs (in shares)			53
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(254)		$ (4)	(250)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(16)
Net loss	(9,575)				(9,575)
Unrealized translation adjustments	21					21
Ending balance at Dec. 31, 2018	104,105	$ 9,482	$ (2,422)	639	96,640	(234)
Ending balance (in shares) at Dec. 31, 2018		31,607	(8,071)
Beginning balance at Sep. 30, 2018	106,974	$ 9,482	$ (2,424)	(451)	100,688	(321)
Beginning balance (in shares) at Sep. 30, 2018		31,607	(8,077)
Share-based compensation	1,147			1,147
Restricted shares issued, net			$ 2	(2)
Restricted shares issued, net (in shares)			7
Shares issued upon exercise of SSARs			$ 1	(1)
Shares issued upon exercise of SSARs (in shares)			2
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(55)		$ (1)	(54)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(3)
Net loss	(4,048)				(4,048)
Unrealized translation adjustments	87					87
Ending balance at Dec. 31, 2018	104,105	$ 9,482	$ (2,422)	639	96,640	(234)
Ending balance (in shares) at Dec. 31, 2018		31,607	(8,071)
Beginning balance at Mar. 31, 2019	100,622	$ 9,482	$ (2,433)	781	93,051	(259)
Beginning balance (in shares) at Mar. 31, 2019		31,607	(8,105)
Share-based compensation	3,479			3,479
Restricted shares issued, net			$ 42	(42)
Restricted shares issued, net (in shares)			143
Shares issued upon exercise of SSARs			$ 5	(5)
Shares issued upon exercise of SSARs (in shares)			17
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(120)		$ (1)	(119)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(5)
Net loss	(7,075)				(7,075)
Unrealized translation adjustments	30					30
Ending balance at Dec. 31, 2019	96,936	$ 9,482	$ (2,387)	4,094	85,976	(229)
Ending balance (in shares) at Dec. 31, 2019		31,607	(7,950)
Beginning balance at Sep. 30, 2019	98,365	$ 9,482	$ (2,386)	2,909	88,558	(198)
Beginning balance (in shares) at Sep. 30, 2019		31,607	(7,949)
Share-based compensation	1,184			1,184
Restricted shares issued, net			$ (1)	1
Restricted shares issued, net (in shares)			(1)
Net loss	(2,582)				(2,582)
Unrealized translation adjustments	(31)					(31)
Ending balance at Dec. 31, 2019	$ 96,936	$ 9,482	$ (2,387)	$ 4,094	$ 85,976	$ (229)
Ending balance (in shares) at Dec. 31, 2019		31,607	(7,950)