Postretirement and Other Employee Benefits (Weighted-Average Actuarial Assumptions) (Details 4)		12 Months Ended
		Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Net periodic benefit cost:
Expected long-term return on plan assets	[1]	3.30%	4.30%	4.40%
Rate of compensation increase		2.70%	2.40%	3.20%
Discount rate		1.90%	2.90%	1.80%
Projected benefit obligation:
Expected long-term return on plan assets		4.00%	3.30%	4.40%
Rate of compensation increase		4.40%	4.10%	4.30%
Discount rate	[2]	2.30%	1.70%	3.20%

[1] ⁽¹⁾ The expected return on plan assets assumption used in calculating net periodic benefit cost is based on historical return experience and estimates of future long-term performance with consideration to the expected investment mix of the plan.

[2] ⁽²⁾ The discount rate is used to state expected cash flows relating to future benefits at a present value on the measurement date. This rate represents the market rate for high-quality fixed income investments whose timing would match the cash out flow of retir ement benefits. Other assumptions include demographic factors such as retirement, mortality and turnover .