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DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Apr. 30, 2021 | Jan. 31, 2021
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION |  |
Cost of property, plant and equipment | $ 7.7 | $ 7.5

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- Definition Amount of costs incurred related to activities to develop a gas-fired power plant to get a fixed asset ready for operation. + References No definition available. + Details
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Namespace Prefix: | agx_
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Balance Type: | debit
Period Type: | duration

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- References No definition available. + Details
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Namespace Prefix: | us-gaap_
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Balance Type: | na
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