REVENUES FROM CONTRACTS WITH CUSTOMERS - Contract Termination (Details) - USD ($) $ in Millions	12 Months Ended	24 Months Ended
Jan. 31, 2025	Jan. 31, 2025
REVENUES FROM CONTRACTS WITH CUSTOMERS
Estimated loss		$ 13.4
Estimated loss, including reversal of net gross profit	$ 3.4

The amount of estimated loss including reversal of net gross profit recorded in previous years.

No definition available.

Name:	agx_EstimatedLossIncludingReversalOfNetGrossProfitRecordedInPreviousYears
Namespace Prefix:	agx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration