Note 15. Stock-Based Compensation (Tables)

12 Months Ended

Aug. 31, 2012

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2012				2011				2010
Term structure of risk-free interest rate		0.13%	-	2.41 %		0.18%	-	1.88 %		0.15%	-	3.30 %
Expected life (years)		7.6	-	9.1		4.0	-	6.5		4.0	-	6.7
Term structure of volatility		29%	-	36 %		23%	-	35 %		27%	-	36 %
Dividend yield			1.16%				1.25%				1.51%
Weighted average estimated fair value			$32.34				$24.78				$20.22
Weighted average exercise price			$93.86				$89.39				$66.35
Fair value as a percentage of exercise price			34.5%				27.7%				30.5%

Employee Stock Purchase Plan Fair Value Determinations [Member]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2012			2011			2010
Risk-free interest rate		0.06	%		0.10	%		0.12	%
Expected life (months)		3			3			3
Expected volatility		14.8	%		11.9	%		13.8	%
Dividend yield		1.26	%		1.04	%		1.33	%

Non-Employee Directors [Member]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Risk-free interest rate	0.94	%
Expected life (years)	5.43
Expected volatility	33.6	%
Dividend yield	1.11	%

Risk-free interest rate	2.13	%
Expected life (years)	5.43
Expected volatility	31.1	%
Dividend yield	1.18	%

Risk-free interest rate	2.54	%
Expected life (years)	5.43
Expected volatility	35.4	%
Dividend yield	1.42	%