XML 49 R51.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Stock-Based Compensation - Option Activity under the Stock-Based Compensation Plan (Detail) (USD $) | Sep. 30, 2013 | Sep. 30, 2012 | May 28, 2012 | Sep. 30, 2011
--- | --- | --- | --- | ---
Option 2009 Plan [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Number of Shares, Options granted |  |  | 20,000 |
Number of Shares, Options outstanding | 318,000 | 318,000 |  | 298,000
Average Exercise Price Per Share, Options granted |  |  | $ 7.150 |
Average Exercise Price Per Share, Options outstanding | $ 7.655 | $ 7.655 |  | $ 7.689
Option 1997 Plan [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Number of Shares, Options outstanding | 27,500 | 27,500 |  | 27,500
Average Exercise Price Per Share, Options outstanding | $ 9.32 | $ 9.32 |  | $ 9.32

X
- Definition Share based compensation arrangement by share based payment award options granted. + References No definition available. + Details
Name: | genc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGranted
Namespace Prefix: | genc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share based compensation arrangements by share based payment award options grants weighted average exercise price. + References No definition available. + Details
Name: | genc_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsWeightedAverageExercisePrice
Namespace Prefix: | genc_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Number of options outstanding, including both vested and non-vested options. + 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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + 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)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant