Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	May 31, 2014	May 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 156,136	$ 147,674
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	25,852	26,941
Stock-based compensation expense	17,425	31,813
Deferred income taxes	(2,038)	2,025
Gain on sale of assets	(62)	(7)
Tax benefits from share-based payment arrangements	(6,815)	(14,858)
Changes in assets and liabilities, net of effects of acquisitions
Accounts receivable, net of reserves	(9,001)	5,006
Accounts payable and accrued expenses	(2,260)	2,276
Accrued compensation	(7,368)	(11,514)
Deferred fees	4,709	2,882
Taxes payable, net of prepaid taxes	20,777	(368)
Prepaid expenses and other assets	(1,931)	1,253
Deferred rent and other non-current liabilities	(1,241)	(927)
Other working capital accounts, net	(461)	1,431
Net cash provided by operating activities	193,722	193,627
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired	(46,873)	(705)
Purchases of investments	(7,818)	(8,406)
Proceeds from sales of investments	6,871	7,500
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(11,704)	(13,288)
Net cash used in investing activities	(59,524)	(14,899)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(44,736)	(40,693)
Repurchase of common stock	(205,154)	(188,066)
Proceeds from employee stock plans	26,799	91,011
Tax benefits from share-based payment arrangements	6,815	14,858
Net cash used in financing activities	(216,276)	(122,890)
Effect of exchange rate changes on cash and cash equivalents	4,309	(2,043)
Net (decrease) increase in cash and cash equivalents	(77,769)	53,795
Cash and cash equivalents at beginning of period	196,627	189,044
Cash and cash equivalents at end of period	$ 118,858	$ 242,839