Consolidated Statements of Income - Unaudited (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Revenues	$ 211,085	$ 196,448
Operating expenses
Cost of services	73,586	66,833
Selling, general and administrative	66,414	62,862
Total operating expenses	140,000	129,695
Operating income	71,085	66,753
Other income	428	277
Income before income taxes	71,513	67,030
Provision for income taxes	21,744	21,486
Net income	$ 49,769	$ 45,544
Basic earnings per common share (in Dollars per share)	$ 1.12	$ 1.01
Diluted earnings per common share (in Dollars per share)	$ 1.11	$ 0.99
Basic weighted average common shares (in Shares)	44,316	45,107
Diluted weighted average common shares (in Shares)	44,984	46,103