Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2013	Nov. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 52,178	$ 49,769
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	8,763	8,917
Stock-based compensation expense	5,116	5,203
Deferred income taxes	(679)	1,766
Gain on sale of assets	(23)	(2)
Tax benefits from share-based payment arrangements	(2,144)	(4,032)
Changes in assets and liabilities, net of effects of acquisition
Accounts receivable, net of reserves	(2,612)	(4,655)
Accounts payable and accrued expenses	(316)	2,851
Accrued compensation	(21,213)	(26,501)
Deferred fees	(94)	410
Taxes payable, net of prepaid taxes	19,108	13,709
Prepaid expenses and other assets	3,036	2,613
Deferred rent and other non-current liabilities	(3,280)	997
Other working capital accounts, net	299	(409)
Net cash provided by operating activities	58,139	50,636
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of business, net of cash acquired	(15,288)	0
Purchases of investments	(7,172)	(7,795)
Proceeds from sales of investments	6,871	7,500
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(5,438)	(6,097)
Net cash used in investing activities	(21,027)	(6,392)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(15,064)	(13,631)
Repurchase of common stock	(60,062)	(28,241)
Proceeds from employee stock plans	9,484	13,102
Tax benefits from share-based payment arrangements	2,144	4,032
Net cash used in financing activities	(63,498)	(24,738)
Effect of exchange rate changes on cash and cash equivalents	3,780	2,162
Net (decrease) increase in cash and cash equivalents	(22,606)	21,668
Cash and cash equivalents at beginning of period	196,627	189,044
Cash and cash equivalents at end of period	$ 174,021	$ 210,712