Acquisitions (Details) (USD $)	3 Months Ended						3 Months Ended		3 Months Ended			3 Months Ended		1 Months Ended			3 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Sep. 12, 2011	Aug. 31, 2011	Nov. 30, 2011 Other Debt [Member]	Aug. 31, 2011 Other Debt [Member]	Nov. 30, 2011 Carnegie Learning Aquisition [Member]	Sep. 12, 2011 Carnegie Learning Aquisition [Member]	Nov. 30, 2011 Carnegie Learning Aquisition [Member] Software technology [Member] Years	Sep. 12, 2011 Carnegie Learning Aquisition [Member] Software technology [Member]	Sep. 12, 2011 Carnegie Learning Aquisition [Member] Trademark [Member]	Nov. 30, 2011 Carnegie Learning Aquisition [Member] Customer relationships [Member] Years	Sep. 12, 2011 Carnegie Learning Aquisition [Member] Customer relationships [Member]	Sep. 30, 2011 Carnegie Mellon Technology Aquisition [Member]	Sep. 12, 2011 Carnegie Mellon Technology Aquisition [Member]	Sep. 12, 2011 Carnegie Mellon Technology Aquisition [Member] Other Debt [Member]	Nov. 30, 2011 Carnegie Mellon Technology Aquisition [Member] Software technology [Member] Years
Purchase price allocation [Line Items]
Amount payable for acquired technology														$ 21,500,000
Time period payable														10-year period
Transaction costs			1,700,000
Net working capital deficit								(336,000)
Property and equipment								870,000
Finite-lived intangible assets										28,000,000			9,000,000
Indefinite-lived intangible assets											14,100,000
Goodwill								34,794,000
Deferred taxes, net								(11,428,000)
Allocated purchase price								75,000,000
Acquisitions, net of acquired cash	73,736,000	0					73,736,000
Less: Cash acquired								(1,264,000)
Finite-lived intangible assets, useful life									5			4					5
Acquired technology															14,400,000
Total debt	$ 114,337,000			$ 599,009,000	$ 33,151,000	$ 21,572,000										$ 14,400,000