Fair Value Of Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	Nov. 30, 2015	Aug. 31, 2015
Fair Value Disclosure [Line Items]
Cash equivalents carried at cost	$ 38.1	$ 41.1
2013 and 2011 Fixed Rate Notes [Member]
Fair Value Disclosure [Line Items]
Long-term Debt, fair Value	425.6
Long-term debt, carrying value, including accrued interest	425.6
2011 Variable Rate Notes [Member]
Fair Value Disclosure [Line Items]
Long-term Debt, fair Value	58.1
Long-term debt, carrying value, including accrued interest	$ 58.1