Debt Instruments Maturity Date

No definition available.

Name:	gy_DebtInstrumentsMaturityDate
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Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtPercentageBearingVariableInterestAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Long-Term Debt - Summary of Long-Term Debt (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended		12 Months Ended
	May 31, 2013	Nov. 30, 2012	May 31, 2013 Term loan due on 2016 [Member]	Nov. 30, 2012 Term loan due on 2016 [Member]	May 31, 2013 Senior subordinated notes [Member]	May 31, 2013 Senior secured notes bearing interest at 7.125% maturing in March 2021 [Member]	Jan. 28, 2013 Senior secured notes bearing interest at 7.125% maturing in March 2021 [Member]	May 31, 2013 Convertible subordinated debentures, bearing interest at 2.25% maturing in November 2024 [Member]	Nov. 30, 2012 Convertible subordinated debentures, bearing interest at 2.25% maturing in November 2024 [Member]	May 31, 2013 Convertible subordinated debentures bearing interest at 4.0625% maturing in December 2034 [Member]	Nov. 30, 2012 Convertible subordinated debentures bearing interest at 4.0625% maturing in December 2034 [Member]	Nov. 30, 2012 Senior subordinated notes due 2012 [Member]	Nov. 30, 2012 Convertible subordinated debentures, bearing interest at 4.0625% maturing in December 2039 [Member]	Dec. 31, 2009 Convertible subordinated debentures, bearing interest at 4.0625% maturing in December 2039 [Member]
Debt Instrument [Line Items]
Term loan, bearing interest at variable rates		3.71%	3.70%
Convertible subordinated debentures, bearing interest						7.125%	7.125%	2.25%	2.25%	4.0625%	4.0625%	9.50%	4.0625%	4.0625%
Term loan, bearing interest at variable rates amount		$ 0.6	$ 0.6
Capital lease, Maturity date	March 2017	March 2017	November 2016	November 2016	March 2021			November 2024	November 2024	December 2034		May 2012	December 2039