Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Restricted Stock Units	Performance Shares	Common Stock	Common Stock Restricted Stock Units	Common Stock Performance Shares	Additional paid in capital	Additional paid in capital Restricted Stock Units	Accumulated deficit	Accumulated other comprehensive income (loss)	Treasury Stock
Beginning Balance, Shares at May. 31, 2021				38,920,951
Beginning Balance at May. 31, 2021	$ 439,457			$ 377			$ 573,507		$ (131,866)	$ 3,153	$ (5,714)
Beginning balance, treasure shares at May. 31, 2021											(370,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(26,547)								(26,547)
Exercise of stock options, Shares				162,721
Exercise of stock options	2,707			$ 1			2,706
Issuance/cancellation of common stock units, Shares					299,544	59,371
Issuance/cancellation of common stock units		$ (1,900)	$ 0					$ (1,900)
Purchase of common stock under Employee Stock Purchase Plan, Shares				98,586
Purchase of common stock under Employee Stock Purchase Plan	1,876			$ 2			1,874
Stock-based compensation	10,692						10,692
Other comprehensive income (loss), net of tax	(1,796)									(1,796)
Ending Balance, Shares at May. 31, 2022				39,541,173
Ending Balance at May. 31, 2022	424,489			$ 380			586,879		(158,413)	1,357	$ (5,714)
Ending balance, treasury shares at May. 31, 2022											(370,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(52,442)								(52,442)
Exercise of stock options, Shares				21,617
Exercise of stock options	156			$ 1			155
Issuance/cancellation of common stock units, Shares				29,826	239,028
Issuance/cancellation of common stock units	(312)	(720)					(312)	(720)
Purchase of common stock under Employee Stock Purchase Plan, Shares				149,778
Purchase of common stock under Employee Stock Purchase Plan	2,047			$ 1			2,046
Stock-based compensation	11,158						11,158
Other comprehensive income (loss), net of tax	$ (6,080)									(6,080)
Ending Balance, Shares at May. 31, 2023	39,611,422			39,981,422
Ending Balance at May. 31, 2023	$ 378,296			$ 382			599,206		(210,855)	(4,723)	$ (5,714)
Ending balance, treasury shares at May. 31, 2023	(370,000,000)										(370,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ (184,349)								(184,349)
Exercise of stock options, Shares	0
Issuance/cancellation of common stock units, Shares				87,377	450,561
Issuance/cancellation of common stock units	$ (546)	$ (305)					(546)	$ (305)
Purchase of common stock under Employee Stock Purchase Plan, Shares				282,237
Purchase of common stock under Employee Stock Purchase Plan	1,603			$ 3			1,600
Stock-based compensation	10,529						10,529
Other comprehensive income (loss), net of tax	$ 358									358
Ending Balance, Shares at May. 31, 2024	40,431,597			40,801,597
Ending Balance at May. 31, 2024	$ 205,586			$ 385			$ 610,484		$ (395,204)	$ (4,365)	$ (5,714)
Ending balance, treasury shares at May. 31, 2024	(370,000,000)										(370,000)