Loss on bank amendment.

No definition available.

Name:	ajrd_LossOnBankAmendment
Namespace Prefix:	ajrd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Unusual Items Expense

+ References

No definition available.

+ Details

Name:	ajrd_UnusualItemsExpense
Namespace Prefix:	ajrd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=34752592&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

+ References

No definition available.

+ Details

Name:	us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

Name:	us-gaap_GainLossRelatedToLitigationSettlement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

+ References

No definition available.

+ Details

Name:	us-gaap_LitigationSettlementAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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_UnusualOrInfrequentItemLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=ajrd_AerospaceandDefenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=us-gaap_CorporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Unusual Items - Schedule of Unusual Items Expense (Details) - USD ($) $ in Millions	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2015	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	May. 31, 2015	May. 31, 2014	Aug. 31, 2015	Aug. 31, 2014	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2013
Unusual or Infrequent Item [Line Items]
Rocketdyne Business acquisition related costs														$ 1.2
Unusual items												$ 51.9	$ 61.7	24.5
Loss on debt repurchased	$ 1.1	$ 0.5	$ 0.2	$ 0.0	$ 9.8	$ 45.9	$ 4.9	$ 0.7	$ 50.8	$ 1.8	$ 60.6	1.9	60.6	5.0
Loss on legal settlement	$ 50.0									$ 50.0		50.0	0.0	0.0
Aerospace and Defense [Member]
Unusual or Infrequent Item [Line Items]
Loss (gain) on legal matters and settlements												50.0	0.9	(1.0)
Rocketdyne Business acquisition related costs												0.0	0.0	2.6
Unusual items												50.0	0.9	1.6
Corporate Segment [Member]
Unusual or Infrequent Item [Line Items]
Rocketdyne Business acquisition related costs												0.0	0.0	17.4
Unusual items												1.9	60.8	22.9
Loss on debt repurchased												1.9	60.6	5.0
Loss on legal settlement												0.0	0.0	0.5
Loss on bank amendment												$ 0.0	$ 0.2	$ 0.0