XML 63 R51.htm IDEA: XBRL DOCUMENT
v3.10.0.1

CUSTOMER CONCENTRATIONS (Details) $ in Millions |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Oct. 31, 2018 USD ($) | Oct. 31, 2018 USD ($) customer | Oct. 31, 2017 customer | Oct. 31, 2018 USD ($) Owner customer | Oct. 31, 2017 customer | Jan. 31, 2018 USD ($) Owner
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners | $ 14.2 | $ 14.2 |  | $ 14.2 |  | $ 69.7
Percentage of amounts retained by project owners |  |  |  | 68.00% |  | 99.00%
Accounts Receivable |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Number of project owners | Owner |  |  |  | 3 |  | 5
Major Customer One |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners | $ 5.4 | 5.4 |  | $ 5.4 |  | $ 19.3
Major Customer One | Accounts Receivable |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of consolidated accounts receivable accounted by major customer | 24.00% |  |  |  |  | 18.00%
Major Customer Two |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners | $ 3.3 | 3.3 |  | 3.3 |  | $ 18.7
Major Customer Two | Accounts Receivable |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of consolidated accounts receivable accounted by major customer |  |  |  |  |  | 18.00%
Major Customer Three |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners | $ 0.9 | $ 0.9 |  | $ 0.9 |  | $ 14.1
Major Customer Four |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners |  |  |  |  |  | 13.4
Major Customer Five |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Amounts retained by project owners |  |  |  |  |  | $ 3.2
Power Services | Revenue |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of major customers or segments |  | 76.00% | 91.00% | 80.00% | 92.00% |
Number of major power industry service customers | customer |  | 4 | 3 | 4 | 4 |
Power Services | Major Customer One | Revenue |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of major customers or segments |  | 20.00% | 36.00% | 18.00% | 29.00% |
Power Services | Major Customer Two | Revenue |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of major customers or segments |  | 17.00% | 24.00% | 16.00% | 27.00% |
Power Services | Major Customer Three | Revenue |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of major customers or segments |  | 13.00% | 13.00% | 12.00% | 16.00% |
Power Services | Major Customer Four | Revenue |  |  |  |  |  |
Customer Concentrations |  |  |  |  |  |
Percentage of major customers or segments |  | 12.00% |  | 11.00% | 14.00% |

X
- Definition Number of major customers. + References No definition available. + Details
Name: | agx_NumberOfMajorCustomers
Namespace Prefix: | agx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of project owners. + References No definition available. + Details
Name: | agx_NumberOfProjectOwners
Namespace Prefix: | agx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of accounts receivable attributable to major customer. + References No definition available. + Details
Name: | agx_PercentageOfAccountsReceivableAttributableToMajorCustomer
Namespace Prefix: | agx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of retained amount under construction contracts. + References No definition available. + Details
Name: | agx_PercentageOfRetainedAmountUnderConstructionContracts
Namespace Prefix: | agx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amounts retained by project owners under construction contracts. + References No definition available. + Details
Name: | agx_RetainedAmountUnderConstructionContracts
Namespace Prefix: | agx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ConcentrationRiskLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=agx_MajorCustomerOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=agx_MajorCustomerTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=agx_MajorCustomerThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=agx_MajorCustomerFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=agx_MajorCustomerFiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=agx_PowerIndustryServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |