Income Taxes (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2012	May 31, 2011	Nov. 30, 2011
Income Tax Contingency [Line Items]
Anticipated Decrease in unrecognized tax benefit during 12 months following current reporting date	$ 200,000		$ 200,000
Income Taxes (Textual) [Abstract]
Income tax benefit (expense)	4,500,000	300,000	4,100,000	(100,000)
Valuation allowance recorded against the net deferred tax assets generated from loss for period	9,700,000	25,700,000	28,000,000	70,800,000
Net deferred tax assets	1,100,000		1,100,000		1,100,000
Valuation allowance	875,800,000		875,800,000		847,800,000
Additions (reductions) in total gross unrecognized tax benefits	(500,000)		(500,000)
Net Increase (reduction) in valuation allowance			28,000,000
Total amount of unrecognized tax benefits, including interest and penalties	1,400,000		1,400,000
State income tax refund	$ 4,100,000		$ 4,376,000	$ 182,000