Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended				0 Months Ended	3 Months Ended			3 Months Ended			3 Months Ended
	Feb. 28, 2014 LegalMatter Y	Aug. 31, 2010	Nov. 30, 2011 LegalMatter Plaintiff	Feb. 28, 2014 Minimum [Member]	Feb. 28, 2014 Maximum [Member]	Feb. 28, 2014 Contracting business [Member]	Mar. 14, 2008 Rio Del Oro property [Member] acre	Feb. 28, 2014 Aerojet Rocketdyne- Sacramento [Member]	Feb. 28, 2014 Aerojet Rocketdyne- Sacramento [Member] Minimum [Member]	Feb. 28, 2014 Aerojet Rocketdyne- Sacramento [Member] Maximum [Member]	Feb. 28, 2014 Aerojet Rocketdyne- BPOU [Member]	Feb. 28, 2014 Aerojet Rocketdyne- BPOU [Member] Minimum [Member]	Feb. 28, 2014 Aerojet Rocketdyne- BPOU [Member] Maximum [Member]	Feb. 28, 2014 Toledo [Member]	Feb. 28, 2014 Toledo [Member] Minimum [Member]	Feb. 28, 2014 Toledo [Member] Maximum [Member]	Feb. 28, 2014 Northrop Agreement [Member]	Feb. 28, 2014 Environmental Protection Agency [Member] acre
Commitment And Contingencies [Line Items]
Unresolved asbestos cases pending	132		16
Accrued estimated liability	$ 0
Number of plaintiffs			271
Reimbursement of legal fees and expenses			1.7
Number of environmental remediation matters	40
Environmental remediation term	15 years
Future estimated environmental costs total				170.4	289.1				128.6	200.8		26.4	56.4		0.2	0.5
Environmental costs above the cumulative limitation	170.4							128.6			26.4						24.2
Environmental obligation funding percent						96.00%
Guarantee obligations								75			25
Additional guarantee obligations								20
Non-contaminated land							400											2,600
Project Agreement term	15
Environmental remediation project termination year											2017-05
Total project cost to complete the project															47	49
Net project costs															23.5	24.5
Environmental costs, increase in Company's share														0.1
Environmental remediation costs, recognition period	15 years
Pre-Close Environmental Costs	20.0
Current annual billing limitation																	6.0
Percentage of environmental costs		12.00%
Increasing percentage of environmental costs		37.00%
Total reimbursable costs under the Northrop Agreement																	$ 189.7