Consolidated Statements Of Cash Flows (USD $) In Thousands	12 Months Ended
Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 171,046	$ 150,211	$ 144,950
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	36,847	37,343	34,337
Stock-based compensation expense	25,773	14,065	13,623
Deferred income taxes	(1,806)	(5,827)	(4,318)
Gain on sale of assets	(22)	(80)	(101)
Tax benefits from share-based payment arrangements	(18,331)	(24,492)	(4,374)
Changes in assets and liabilities, net of effects of acquisition
Accounts receivable, net of reserves	(15,311)	3,883	12,005
Accounts payable and accrued expenses	188	(1,308)	3,081
Accrued compensation	(7,882)	7,440	4,212
Deferred fees	3,219	(7,759)	(526)
Taxes payable, net of prepaid taxes	20,387	35,781	1,547
Prepaid expenses and other assets	(6,597)	281	(3,163)
Deferred rent and other non-current liabilities	(676)	(359)	3,209
Other working capital accounts, net	301	1,901	3,288
Net cash provided by operating activities	207,136	211,080	207,770
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of business, net of cash acquired	0	(55,180)	0
Proceeds from sales of investments	0	0	25,260
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(29,343)	(20,768)	(24,040)
Net cash (used in) provided by investing activities	(29,343)	(75,948)	1,220
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(43,949)	(38,494)	(34,770)
Repurchase of common stock	(216,584)	(192,816)	(103,827)
Proceeds from employee stock plans	43,079	55,250	23,804
Tax benefits from share-based payment arrangements	18,331	24,492	4,374
Net cash used in financing activities	(199,123)	(151,568)	(110,419)
Effect of exchange rate changes on cash and cash equivalents	7,274	(4,143)	(237)
Net (decrease) increase in cash and cash equivalents	(14,056)	(20,579)	98,334
Cash and cash equivalents at beginning of year	195,741	216,320	117,986
Cash and cash equivalents at end of year	181,685	195,741	216,320
Supplemental Disclosure of Cash Flow Information
Cash paid during the year for income taxes	36,869	38,450	64,536
Supplemental Disclosure of Non-Cash Transactions
Dividends declared, not paid	$ 12,165	$ 10,586	$ 9,348

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7

-Footnote 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016