Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Restricted Stock Units	Common Stock	Common Stock Restricted Stock Units	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, 2020			38,448,536
Beginning Balance at May. 31, 2020	$ 454,872		$ 374		$ 561,871		$ (100,318)	$ (1,341)	$ (5,714)
Beginning balance, treasure shares at May. 31, 2020									(370,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(31,548)						(31,548)
Exercise of stock options, Shares			123,536
Exercise of stock options	1,930		$ 1		1,929
Issuance/cancellation of common stock units, Shares				184,685
Issuance/cancellation of common stock units		$ (223)				$ (223)
Purchase of common stock under Employee Stock Purchase Plan, Shares			164,194
Purchase of common stock under Employee Stock Purchase Plan	1,307		$ 2		1,305
Stock-based compensation	8,625				8,625
Other comprehensive income (loss), net of tax	4,494							4,494
Ending Balance at May. 31, 2021	439,457		$ 377		573,507		(131,866)	3,153	$ (5,714)
Ending Balance, Shares at May. 31, 2021			38,920,951
Ending balance, treasury 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			59,371	299,544
Issuance/cancellation of common stock units		(1,900)				(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 at May. 31, 2022	$ 424,489		$ 380		586,879		(158,413)	1,357	$ (5,714)
Ending Balance, Shares at May. 31, 2022	39,171,173		39,541,173
Ending balance, treasury shares at May. 31, 2022	(370,000,000)								(370,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ (52,442)						(52,442)
Exercise of stock options, Shares	47,824		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 at May. 31, 2023	$ 378,296		$ 382		$ 599,206		$ (210,855)	$ (4,723)	$ (5,714)
Ending Balance, Shares at May. 31, 2023	39,611,422		39,981,422
Ending balance, treasury shares at May. 31, 2023	(370,000,000)								(370,000)