Consolidated Statements of Income (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	May 31, 2011	May 31, 2010	May 31, 2011	May 31, 2010
Consolidated Statements of Income
Revenues	$ 183,647	$ 160,301	$ 534,571	$ 472,825
Operating expenses
Cost of services	62,224	51,355	179,146	152,632
Selling, general and administrative	59,600	53,262	176,080	155,989
Total operating expenses	121,824	104,617	355,226	308,621
Operating income	61,823	55,684	179,345	164,204
Other income	172	86	429	475
Income before income taxes	61,995	55,770	179,774	164,679
Provision for income taxes	18,684	17,112	49,608	53,759
Net income	$ 43,311	$ 38,658	$ 130,166	$ 110,920
Basic earnings per common share	$ 0.94	$ 0.83	$ 2.82	$ 2.37
Diluted earnings per common share	$ 0.92	$ 0.81	$ 2.75	$ 2.30
Weighted average common shares (Basic)	45,969	46,544	46,145	46,872
Weighted average common shares (Diluted)	47,154	47,725	47,418	48,183