Unusual Items - Summary of Loss Incurred on Repurchase of Debt Instruments (Detail) (4.0625 Percentage Convertible Subordinated Debentures [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
Feb. 28, 2014
4.0625 Percentage Convertible Subordinated Debentures [Member]
Unusual or Infrequent Item [Line Items]
Principal amount repurchased	$ 4.5
Cash repurchase price	(9.4)
Loss on 4 1/16% Debentures repurchased	$ (4.9)

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

No definition available.

Name:	us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration