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: