Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	Aug. 31, 2015	Nov. 30, 2014
Fair Value, Inputs, Level 1
Fair Value, Measurement Inputs, Disclosure [Line Items]
Money market funds	$ 63.5
Fair Value, Inputs, Level 2
Fair Value, Measurement Inputs, Disclosure [Line Items]
Long-term debt excluding credit facilities, fair value	286.7	$ 291.2
Long-term debt excluding credit facilities, carrying amount	$ 270.9	$ 271.7