Stockholders' Equity (Black-Scholes Option Pricing Model) (Details 7)		12 Months Ended
		Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Schedule of Weighted Average Assumptions for Fair Values of Stock Options[Line Items]
Expected dividend yield		0.80%	0.70%	0.80%
Risk-free interest rate		0.50%	0.30%	0.10%
Expected volatility	[1]	33.00%	28.10%	24.50%
Expected life		6 months	6 months	6 months

[1] (1) The expected volatility was estimated using the historical volatility derived from the Company's common stock.