Consolidated Statements of Shareholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common stock [Member]	Treasury stock [Member]	Capital in excess of stated value [Member]	Retained Earnings [Member]	Accumulated other comprehensive income (loss) [Member]
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 inaccounting policy	2,614				2,614
Share-based compensation	3,971			3,971
Restricted shares issued, net			$ 54	(54)
Restricted shares issued, net (in shares)			180
Shares issued upon exercise of stock options and SSARs			$ 18	(18)
Shares issued upon exercise of stock options and SSARs (in shares)			60
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(1,226)		$ (19)	(1,207)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(62)
Net loss	(13,164)				(13,164)
Unrealized translation adjustments	(4)					(4)
Ending balance at Mar. 31, 2019	100,622	$ 9,482	$ (2,433)	781	93,051	(259)
Ending balance (in shares) at Mar. 31, 2019		31,607	8,105
Share-based compensation	5,682			5,682
Restricted shares issued, net			$ 41	(41)
Restricted shares issued, net (in shares)			140
Shares issued upon exercise of stock options and SSARs			$ 6	(6)
Shares issued upon exercise of stock options and SSARs (in shares)			21
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(940)		$ (15)	(925)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(53)
Net loss	(34,067)				(34,067)
Unrealized translation adjustments	460					460
Ending balance at Mar. 31, 2020	71,757	$ 9,482	$ (2,401)	5,491	58,984	201
Ending balance (in shares) at Mar. 31, 2020		31,607	7,997
Share-based compensation	40,066			40,066
Restricted shares issued, net			$ 28	(28)
Restricted shares issued, net (in shares)			90
Shares issued upon exercise of stock options and SSARs			$ 141	(141)
Shares issued upon exercise of stock options and SSARs (in shares)			467
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares	(8,177)		$ (46)	(8,131)
Shares withheld for taxes upon exercise of stock options, SSARs or vesting of restricted shares (in shares)			(156)
Net loss	(21,001)				(21,001)
Series A convertible preferred stock issuance costs	(1,031)				(1,031)
Series A convertible preferred stock dividends	(1,576)				(1,576)
Unrealized translation adjustments	(162)					(162)
Ending balance at Mar. 31, 2021	$ 79,876	$ 9,482	$ (2,278)	$ 37,257	$ 35,376	$ 39
Ending balance (in shares) at Mar. 31, 2021		31,607	7,596