Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Nov. 30, 2016		Aug. 31, 2016
Assets:
Nonqualified savings plan investments	$ 17,161		$ 15,864
Fair Value, Measurements, Recurring
Assets:
Derivative financial instruments	766		1,595
Nonqualified savings plan investments	17,161		15,864
Cash equivalents	5,077		5,077
Assets, Fair Value Disclosure, Total	23,004		22,536
Liabilities:
Derivative financial instruments	13,341		7,466
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Assets:
Nonqualified savings plan investments	17,161		15,864
Cash equivalents	5,077		5,077
Assets, Fair Value Disclosure, Total	22,238		20,941
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Assets:
Derivative financial instruments	766	[1]	1,595
Assets, Fair Value Disclosure, Total	766	[1]	1,595
Liabilities:
Derivative financial instruments	$ 13,341	[1]	$ 7,466

[1] Level 2 assets and liabilities include derivative financial instruments that are valued based on observable inputs. See Note 10 Derivative Instruments for further discussion.