Consolidated Statements of Cash Flows - Unaudited (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 49,769	$ 45,544
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	8,917	8,403
Stock-based compensation expense	5,203	5,880
Deferred income taxes	1,766	57
Gain on sale of assets	(2)	(1)
Tax benefits from share-based payment arrangements	(4,032)	(3,178)
Changes in assets and liabilities
Accounts receivable, net of reserves	(4,655)	10,171
Accounts payable and accrued expenses	2,851	2,839
Accrued compensation	(26,501)	(24,523)
Deferred fees	410	(1,279)
Taxes payable, net of prepaid taxes	13,709	10,979
Prepaid expenses and other assets	2,613	539
Deferred rent and other non-current liabilities	997	(611)
Other working capital accounts, net	(409)	(66)
Net cash provided by operating activities	50,636	54,754
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of investments	(7,795)	(15,000)
Proceeds from sales of investments	7,500	0
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(6,097)	(6,054)
Net cash used in investing activities	(6,392)	(21,054)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(13,631)	(12,084)
Repurchase of common stock	(28,241)	(14,732)
Proceeds from employee stock plans	13,102	7,420
Tax benefits from share-based payment arrangements	4,032	3,178
Net cash used in financing activities	(24,738)	(16,218)
Effect of exchange rate changes on cash and cash equivalents	2,162	(5,413)
Net increase in cash and cash equivalents	21,668	12,069
Cash and cash equivalents at beginning of period	189,044	181,685
Cash and cash equivalents at end of period	$ 210,712	$ 193,754