Stock-Based Compensation (Tables)

12 Months Ended

Aug. 31, 2011

Aug. 31, 2010

Aug. 31, 2009

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-Based Compensation Expense

	2011			2010			2009
Stock-based compensation	$	25,773	*	$	14,065		$	13,623
Tax impact of stock-based compensation		(7,990	)		(4,627	)		(4,550	)
Stock-based compensation, net of tax	$	17,783		$	9,438		$	9,073

* Included in fiscal 2011 was a pre-tax stock-based compensation charge of $7.9 million ($5.4 million after-tax) from an increase in the estimated number of performance-based options that will vest due to accelerating levels of ASV and diluted EPS than previously expected. The revised estimate reflects a higher performance level than previously estimated and accordingly, increased the number of performance-based options that will vest and be expensed.

Summary Of Stock Option Weighted Average Assumptions

	2011		2010		2009
Term structure of risk-free interest rate		0.18% - 1.88%		0.15% -  3.30%		0.89% -  3.09%
Expected life		4.0- 6.5 years		4.0- 6.7 years		5.0- 5.4 years
Term structure of volatility		23% - 35%		27% - 36%		33% - 38%
Dividend yield		1.25%		1.51%		2.01%
Weighted average estimated fair value	$	24.78	$	20.22	$	9.39
Weighted average exercise price	$	89.39	$	66.35	$	36.00
Fair value as a percentage of exercise price		27.7%		30.5%		26.1%

Employee Stock Purchase Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary Of Stock Option Weighted Average Assumptions

	2011			2010			2009
Risk-free interest rate		0.10	%		0.12	%		0.31	%
Expected life		3 months			3 months			3 months
Expected volatility		11.9	%		13.8	%		24.6	%
Dividend yield		1.04	%		1.33	%		1.72	%

Non-Employee Directors' Stock Option Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary Of Stock Option Weighted Average Assumptions

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

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

Risk-free interest rate	1.45	%
Expected life	5.51 years
Expected volatility	35.2	%
Dividend yield	1.70	%