Share-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Share-based compensation expense [Line Items]
Share-based compensation expense	$ 10,537	$ 10,626	$ 22,510	$ 27,515
Instructional and student advisory [Member]
Share-based compensation expense [Line Items]
Share-based compensation expense	3,280	5,614	6,813	13,202
Marketing [Member]
Share-based compensation expense [Line Items]
Share-based compensation expense	937	1,054	2,045	3,097
Admissions advisory [Member]
Share-based compensation expense [Line Items]
Share-based compensation expense	212	196	314	366
General and administrative [Member]
Share-based compensation expense [Line Items]
Share-based compensation expense	5,644	3,399	11,012	9,422
Restructuring and other charges [Member]
Share-based compensation expense [Line Items]
Share-based compensation expense	$ 464	$ 363	$ 2,326	$ 1,428