Income Tax Examinations by Tax Authorities in its Major Tax Jurisdictions (Detail)	12 Months Ended
	Sep. 30, 2016
U.S. Federal
Income Tax Examination [Line Items]
Income Tax Examination, Years No Longer Subject To Audit	2012 and prior
Canada
Income Tax Examination [Line Items]
Income Tax Examination, Years No Longer Subject To Audit	2007 and prior
France
Income Tax Examination [Line Items]
Income Tax Examination, Years No Longer Subject To Audit	2012 and prior
United Kingdom
Income Tax Examination [Line Items]
Income Tax Examination, Years No Longer Subject To Audit	2013 and prior