Product Warranty, Period

No definition available.

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- Definition

Surety Bond Outstanding

+ References

No definition available.

+ Details

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Namespace Prefix:	gy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value at acquisition-date of the equity interest in the acquiree held by the acquirer, immediately before the acquisition date for businesses combined in stages.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Percentage of voting equity interests acquired in a business combination achieved in stages, including equity interests in the acquiree held by the acquirer immediately before the acquisition date and acquired at the acquisition date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Details

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

Arrangements with Off-Balance Sheet Risk - Narrative (Detail) (USD $)	0 Months Ended	9 Months Ended
	Jun. 14, 2013	Aug. 31, 2014	Jun. 14, 2013
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Outstanding surety bonds		$ 43,700,000
Guarantee obligations		120,000,000
Standard warranty period		1 year
Rocketdyne Business [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Amount related to the pending future acquisition of UTC's ownership	55,000,000	55,000,000
Expected future acquisition of ownership interest percentage		50.00%	50.00%
Senior Credit Facility [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Outstanding commercial letters of credit		$ 58,100,000