Weighted Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost (Detail) - United States Pension Plan of US Entity	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Assumptions for benefit obligations:
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	3.45%	4.45%
Assumptions for net periodic benefit cost:
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.45%	4.45%	4.15%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets	7.15%	7.40%	7.50%