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DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details) | 6 Months Ended
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Jul. 31, 2018 | Jul. 31, 2017
GPS |  |
Description of the Business |  |
Consolidated revenues by subsidiaries | 65.00% | 89.00%

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- Definition Represents the entity's revenue contributed to the parent entity as a percentage of the parent entity's total revenue. + References No definition available. + Details
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Namespace Prefix: | agx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Schedule Of Description Of Business [Line Items] + References No definition available. + Details
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Namespace Prefix: | agx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |