Commitments and Contingencies - Narrative - Legal Matters (Detail) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014 Asbestos Litigation [Member] LegalMatter	Nov. 30, 2011 AMEC PLC [Member] Asbestos Litigation [Member] LegalMatter plantiff	Aug. 31, 2014 AMEC PLC [Member] Asbestos Litigation [Member]
Loss Contingencies [Line Items]
Unresolved asbestos cases pending					125	16
Accrued estimated liability					$ 0
Number of plaintiffs						271
Reimbursement of legal fees and expenses						1,700,000
Legal fees and expenses	100,000	(200,000)	200,000	200,000		2,700,000
Estimate of liability accrued							$ 0