Summary of Significant Accounting Policies - Consolidated Statement of Operations on Land Sale (Details) - Land - Hillsborough - Held-for-sale $ in Millions	12 Months Ended
Nov. 30, 2015 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales from land sale	$ 42.0
Cost of sales from land sale	11.4
Income before income taxes from land sale	30.6
Income tax provision related to land sale	12.7
Net income from land sale	$ 17.9

Disposal Group, Including Discontinued Operation, Income Tax Expense (Benefit)

No definition available.

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

- Definition

Income (Loss) From Disposal Group, Excluding Discontinued Operations, Net Of Tax

+ References

No definition available.

+ Details

Name:	ajrd_IncomeLossFromDisposalGroupExcludingDiscontinuedOperationsNetOfTax
Namespace Prefix:	ajrd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of costs of goods sold attributable to disposal group, including, but not limited to, discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

+ Details

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

- Definition

Amount of gross profit attributable to disposal group, including, but not limited to, discontinued operation.

+ References

+ Details

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

- Definition

Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

+ References

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue
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_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ajrd_HillsboroughMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldForSaleOrDisposedOfBySaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: