Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Revenues	$ 231,761	$ 214,613	$ 681,671	$ 638,779
Operating expenses
Cost of services	90,661	76,721	261,165	226,148
Selling, general and administrative	68,063	66,255	197,673	213,746
Total operating expenses	158,724	142,976	458,838	439,894
Operating income	73,037	71,637	222,833	198,885
Other income	334	361	1,018	1,146
Income before income taxes	73,371	71,998	223,851	200,031
Provision for income taxes	21,839	18,631	67,715	52,357
Net income	$ 51,532	$ 53,367	$ 156,136	$ 147,674
Basic earnings per common share (in Dollars per share)	$ 1.22	$ 1.21	$ 3.66	$ 3.35
Diluted earnings per common share (in Dollars per share)	$ 1.21	$ 1.20	$ 3.62	$ 3.30
Basic weighted average common shares (in Shares)	42,166	43,954	42,615	44,028
Diluted weighted average common shares (in Shares)	42,615	44,485	43,170	44,784