Note 14. Stock-Based Compensation (Tables)

3 Months Ended

Nov. 30, 2011

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

	Three Months Ended  November 30,
	2011			2010
Stock-based compensation	$	5,880		$	3,677
Tax impact of stock-based compensation		(1,887	)		(1,195	)
Stock-based compensation, net of tax	$	3,993		$	2,482

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

		Q1 2012			Q1 2011
Term structure of risk-free interest rate		0.13% - 2.41	%		0.18% - 1.88	%
Expected life	7.56 - 7.75 years			5.75 - 6.51 years
Term structure of volatility		30% - 36	%		26% - 34	%
Dividend yield		1.11	%		1.25	%
Weighted average estimated fair value	$	32.08		$	24.42

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

Three months ended November 30,	2011			2010
Risk-free interest rate		0.02	%		0.14	%
Expected life	3 months			3 months
Expected volatility		18	%		10	%
Dividend yield		1.25	%		1.20	%