Note 14. Stock-Based Compensation (Tables)

9 Months Ended

May 31, 2012

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Three Months Ended May 31,						Nine Months Ended May 31
	2012			2011			2012			2011
Stock-based compensation	$	5,149		$	4,975		$	17,074		$	15,352
Tax effect of stock-based compensation*		(1,565	)		(1,500	)		(5,321	)		(4,752	)
Stock-based compensation, net of tax	$	3,584		$	3,475		$	11,753		$	10,600

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

	Three Months Ended May 31,				Nine Months Ended May 31,
	2012	2011			2012			2011
Term structure of risk-free interest rate	n/a		0.19% - 1.00	%		0.13% - 2.41	%		0.18% - 1.88	%
Expected life	n/a	4.0 years			7.6 – 7.8 years			4.0 - 6.5 years
Term structure of volatility	n/a		23% - 35	%		30% - 36	%		23% - 35	%
Dividend yield	n/a		1.07	%		1.11	%		1.25	%
Weighted average estimated fair value	n/a	$	23.41		$	32.08		$	24.72

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used

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

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

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

	Three Months Ended May 31,
	2012			2011
Risk-free interest rate		0.09	%		0.07	%
Expected life	3 months			3 months
Expected volatility		12.1	%		9.8	%
Dividend yield		1.4	%		0.9	%

	Nine Months Ended May 31,
	2012			2011
Risk-free interest rate		0.05	%		0.12	%
Expected life	3 months			3 months
Expected volatility		14.1	%		9.7	%
Dividend yield		1.3	%		1.0	%