Acquisitions (Details) (USD $)	9 Months Ended					9 Months Ended		9 Months Ended			9 Months Ended		1 Months Ended				9 Months Ended
	May 31, 2012	May 31, 2011	Aug. 31, 2011	May 31, 2012 Other Debt [Member]	Aug. 31, 2011 Other Debt [Member]	May 31, 2012 Carnegie Learning Aquisition [Member]	Sep. 12, 2011 Carnegie Learning Aquisition [Member]	May 31, 2012 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]	May 31, 2012 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]	May 31, 2012 Carnegie Mellon Technology Aquisition [Member] Other Debt [Member]	Sep. 12, 2011 Carnegie Mellon Technology Aquisition [Member] Other Debt [Member]	May 31, 2012 Carnegie Mellon Technology Aquisition [Member] Software technology [Member] Years
Purchase price allocation [Line Items]
Amount payable for acquired technology													$ 21,500,000
Debt term															10 years
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	$ 125,994,000		$ 599,009,000	$ 31,703,000	$ 21,572,000											$ 14,400,000