Consolidated Statements of Comprehensive Income Statement (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Nov. 30, 2013	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2011
Net income (loss)	$ 28,116	$ 27,278	$ (2,973)	$ (12,458)	$ 7,724	$ 3,261	$ (24,136)	$ (45,802)	$ 39,963	$ (58,953)	$ (178,768)
Net actuarial gain (loss) arising during the period									7,083	(4,765)	(5,646)
Amortization of net actuarial loss									(1,803)	(1,403)	(595)
Amortization of prior service cost									1,556	1,556	1,556
Other comprehensive income (loss)									10,442	(1,806)	(3,495)
Comprehensive income (loss)									$ 50,405	$ (60,759)	$ (182,263)