Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Aug. 31, 2013		Aug. 31, 2012		Aug. 31, 2011
Revenues	$ 858,112	[1]	$ 805,793	[1]	$ 726,510	[1]
Operating expenses
Cost of services	306,379		275,537		244,623
Selling, general and administrative	282,314		257,266		243,552
Total operating expenses	588,693		532,803		488,175
Operating income	269,419		272,990		238,335
Other income	1,491		1,715		623
Income before income taxes	270,910		274,705		238,958
Provision for income taxes	72,273	[2]	85,896		67,912	[3]
Net income	$ 198,637		$ 188,809		$ 171,046
Basic earnings per common share (in Dollars per share)	$ 4.53		$ 4.22		$ 3.72
Diluted earnings per common share (in Dollars per share)	$ 4.45		$ 4.12		$ 3.61
Weighted average common shares (Basic) (in Shares)	43,890		44,784		45,953
Weighted average common shares (Diluted) (in Shares)	44,624		45,810		47,355

[1] Revenues are attributed to countries based on the location of the client.

[2] Includes income tax benefits of $7.2 million primarily from the reenactment of the U.S. Federal R&D tax credit in January 2013 and the finalization of the fiscal 2012 tax return. The reenactment of the credit was retroactive to January 1, 2012 and extends through the end of the 2013 calendar year. The fiscal 2013 annual effective tax rate before discrete items of $7.2 million was 28.9%.

[3] Includes income tax benefits of $6.3 million from the finalization of the fiscal 2010 tax return and the reenactment of the U.S. Federal R&D tax credit in December 2010. The fiscal 2011 annual effective tax rate before discrete items of $6.3 million was 30.9%.