Income Taxes - Reconciliation of the beginning and ending amount of the valuation allowance (Details) - USD ($) $ in Thousands	12 Months Ended
May 31, 2025	May 31, 2024
Income Taxes
Valuation allowance at beginning of year	$ 128,636	$ 128,579
Change in valuation allowance	(2,433)	57
Valuation allowance at end of year	$ 126,203	$ 128,636

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant