Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2011	Aug. 31, 2011
Accrued liabilities [Abstract]
Securities class action liability	$ 161,000	$ 161,150
Salaries, wages and benefits	94,238	93,763
Accrued advertising	41,150	50,172
Accrued professional fees	31,284	32,607
Student refunds, grants and scholarships	14,459	17,360
Other accrued liabilities	37,640	43,754
Total accrued liabilities	$ 379,771	$ 398,806