Consolidated Statements of Comprehensive Income (Loss) (USD $) In Millions, 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
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
Net income (loss)	$ (3.7)	$ 197.4	$ (11.8)	$ (14.0)	$ 2.8	$ (9.5)	$ 1.7	$ 2.4	$ 167.9	$ (2.6)	$ 2.9
Other comprehensive income (loss):
Amortization of net actuarial losses, net of $1.2 million of income taxes in fiscal 2013									91.3	58.9	62.8
Actuarial gains (losses) arising during the period, net of $2.2 million of income taxes in fiscal 2013									173.5	(245.7)	(81.1)
Amortization of prior service credits (costs), net of $0.1 million of income taxes in fiscal 2013									(0.9)	(0.1)	0.1
Comprehensive income (loss)									$ 431.8	$ (189.5)	$ (15.3)