Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Feb. 29, 2012	Feb. 28, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 92,290	$ 86,855
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	16,692	18,758
Stock-based compensation expense	11,925	10,377
Deferred income taxes	(91)	(1,275)
Gain on sale of assets	(1)	(4)
Tax benefits from share-based payment arrangements	(4,973)	(12,919)
Changes in assets and liabilities
Accounts receivable, net of reserves	3,545	(10,808)
Accounts payable and accrued expenses	155	(788)
Accrued compensation	(16,298)	(19,853)
Deferred fees	697	2,765
Taxes payable, net of prepaid taxes	(3,372)	2,849
Prepaid expenses and other assets	(456)	(3,052)
Deferred rent and other non-current liabilities	(922)	139
Other working capital accounts, net	(732)	(563)
Net cash provided by operating activities	98,459	72,481
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of investments	(15,000)	0
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(10,644)	(15,433)
Net cash used in investing activities	(25,644)	(15,433)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(24,182)	(21,110)
Repurchase of common stock	(59,795)	(75,145)
Proceeds from employee stock plans	13,843	27,961
Tax benefits from share-based payment arrangements	4,973	12,919
Net cash used in financing activities	(65,161)	(55,375)
Effect of exchange rate changes on cash and cash equivalents	(4,341)	5,691
Net increase in cash and cash equivalents	3,313	7,364
Cash and cash equivalents at beginning of period	181,685	195,741
Cash and cash equivalents at end of period	$ 184,998	$ 203,105