Note 14 - Stock-Based Compensation (Tables)

12 Months Ended

Aug. 31, 2013

Note 14 - Stock-Based Compensation (Tables) [Line Items]

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

	2013			2012			2011
Term structure of risk-free interest rate	0.16%	-	1.91%	0.13%	-	2.41%	0.18%	-	1.88%
Expected life (years)	7.6	-	7.8	7.6	-	9.1	4.0	-	6.5
Term structure of volatility	24%	-	33%	29%	-	36%	23%	-	35%
Dividend yield		1.30%			1.16%			1.25%
Weighted average estimated fair value		$26.87			$32.34			$24.78
Weighted average exercise price		$92.22			$93.86			$89.39
Fair value as a percentage of exercise price		29.1%			34.5%			27.7%

Non-Employee Stock Option Plan [Member]

Note 14 - Stock-Based Compensation (Tables) [Line Items]

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

Risk-free interest rate	0.89	%
Expected life (years)	5.4
Expected volatility	32	%
Dividend yield	1.30	%

Risk-free interest rate	0.94	%
Expected life (years)	5.4
Expected volatility	34	%
Dividend yield	1.11	%

Risk-free interest rate	2.13	%
Expected life (years)	5.4
Expected volatility	31	%
Dividend yield	1.18	%

Employee Stock Purchase Plan [Member]

Note 14 - Stock-Based Compensation (Tables) [Line Items]

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

	2013			2012			2011
Risk-free interest rate		0.07	%		0.06	%		0.10	%
Expected life (months)		3			3			3
Expected volatility		9.8	%		14.8	%		11.9	%
Dividend yield		1.38	%		1.26	%		1.04	%