Fair Value Disclosures (Details) (USD $) In Thousands	9 Months Ended	12 Months Ended
	Aug. 31, 2011	Nov. 30, 2010
Significant Prices in Other Observable Inputs Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Long-lived assets held and used	$ 75	$ 1,877
Significant Unobservable Inputs Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Long-lived assets held and used	29,788	9,693
Estimate of Fair Value, Fair Value Disclosure [Member]
Assets measured at fair value on a nonrecurring basis
Long-lived assets held and used	29,900	11,600
Fair Value, Measurements, Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Long-lived assets held and used	$ 29,863	$ 11,570