CASH, CASH EQUIVALENTS AND INVESTMENTS - Concentration Risk (Details)	Apr. 30, 2025	Jan. 31, 2025
CASH, CASH EQUIVALENTS AND INVESTMENTS
Percentage of cash and cash equivalents held by financial institutions	14.00%	2.00%

Percentage of company's cash and cash equivalents held by financial institutions.

No definition available.

Name:	agx_PercentageOfCashAndCashEquivalentsHeldByFinancialInstitutions
Namespace Prefix:	agx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant