XML 29 R52.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Stock-Based Compensation - Additional Information (Detail) (USD $) | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 30, 2003 Person | Jan. 31, 2014 | Jan. 31, 2013 | Jan. 31, 2012 | Jan. 31, 2014 ISOs [Member] | Jan. 31, 2014 NSOs [Member] | Jan. 31, 2014 Restricted Stock [Member] | Jan. 31, 2013 Restricted Stock [Member] | Jan. 31, 2012 Restricted Stock [Member] | Jan. 31, 2014 Employee Stock Option [Member] | Jun. 30, 2013 Stock Plan [Member] | Jan. 31, 2014 Stock Plan [Member] | Jan. 31, 2014 Stock Option Plan [Member] | Jan. 31, 2014 Two Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of additional common stock authorized for issuance |  |  |  |  |  |  |  |  |  |  | 750,000 |  |  |
Number of common stock authorized for issuance |  |  |  |  |  |  |  |  |  |  | 1,250,000 |  |  |
Expiration dates of stock incentive plans |  |  |  |  |  |  |  |  |  |  |  | 2021-07 | 2011-07 |
Incentive stock option award maximum expiration period |  |  |  |  | 10 years | 10 years |  |  |  |  |  |  |  |
Period to become exercisable |  |  |  |  | 1 year | 1 year | 2 years |  |  |  |  |  |  |
Number of shares of common stock reserved for issuance |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,448,650
Number of shares of common stock available for award at January 31, 2014 |  |  |  |  |  |  |  |  |  |  |  | 532,500 |  |
Intrinsic value of the stock options exercised |  | $ 3,158,000 | $ 1,242,000 | $ 238,000 |  |  |  |  |  |  |  |  |  |
Intrinsic value of outstanding stock options |  | 10,124,000 |  |  |  |  |  |  |  |  |  |  |  |
Intrinsic value of exercisable stock options |  | 7,977,000 |  |  |  |  |  |  |  |  |  |  |  |
Compensation expense |  | 1,536,000 | 1,316,000 | 637,000 |  |  |  |  |  |  |  |  |  |
Unrecognized compensation cost |  | 825,000 |  |  |  |  |  |  |  |  |  |  |  |
Compensation expense recognize, period |  |  |  |  |  |  |  |  |  | 2014-12 |  |  |  |
Method used for fair value assumption |  | Black-Scholes option-pricing model |  |  |  |  |  |  |  |  |  |  |  |
Volatility rate, minimum |  | 0.73% | 1.82% | 1.98% |  |  |  |  |  |  |  |  |  |
Volatility rate, maximum |  | 1.52% | 2.01% | 3.42% |  |  |  |  |  |  |  |  |  |
Stock options awarded, minimum |  | 32.30% | 34.50% | 36.10% |  |  |  |  |  |  |  |  |  |
Stock options awarded, maximum |  | 34.30% | 36.40% | 57.60% |  |  |  |  |  |  |  |  |  |
Market value of the shares amortized |  |  |  |  |  |  | 10,000 | 25,000 | 15,000 |  |  |  |  |
Restricted stock awarded to employee |  |  |  |  |  |  |  |  | 5,000 |  |  |  |  |
Warrants converted to shares of common stock |  |  | 160,000 |  |  |  |  |  |  |  |  |  |  |
Conversion price for outstanding warrants |  |  | 7.75 |  |  |  |  |  |  |  |  |  |  |
Number of individual to whom warrants issued | 3 |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate fair value of the warrants | 849,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Company's expense for defined contribution savings plans |  | 677,000 | 36,000 | 31,000 |  |  |  |  |  |  |  |  |  |
Defined contribution plan, profit-sharing contribution |  | $ 404,000 |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Aggregate market value of restricted stock award. + References No definition available. + Details
Name: | agx_AggregateMarketValueOfRestrictedStockAward
Namespace Prefix: | agx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined contribution plan employer discretionary profit sharing contribution amount. + References No definition available. + Details
Name: | agx_DefinedContributionPlanEmployerDiscretionaryProfitSharingContributionAmount
Namespace Prefix: | agx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Employee service share based compensation nonvested awards compensation cost not yet recognized period for recognition. + References No definition available. + Details
Name: | agx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedPeriodForRecognition
Namespace Prefix: | agx_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of warrant. + References No definition available. + Details
Name: | agx_FairValueOfWarrant
Namespace Prefix: | agx_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of individual to whom warrants issued. + References No definition available. + Details
Name: | agx_NumberOfIndividualToWhomWarrantsIssued
Namespace Prefix: | agx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award maximum expiration period. + References No definition available. + Details
Name: | agx_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumExpirationPeriod
Namespace Prefix: | agx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award number of shares reserved for issuance. + References No definition available. + Details
Name: | agx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesReservedForIssuance
Namespace Prefix: | agx_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The expiration date of the option plan. + References No definition available. + Details
Name: | agx_ShareBasedCompensationArrangementByShareBasedPaymentPlanExpirationMonth
Namespace Prefix: | agx_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Warrants converted to shares of common stock. + References No definition available. + Details
Name: | agx_WarrantsConvertedToSharesOfCommonStock
Namespace Prefix: | agx_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 4 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsMethodUsed
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
Name: | us-gaap_StockOptionPlanExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration