Unusual Items - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2011
Unusual or Infrequent Item [Line Items]
Legal settlement charge	$ 0.5
Realized (gains)losses and interest	(1.0)	0.7	0.8
Expenses incurred related to Business acquisition	20.0	11.6
Internal labor costs	1.4	2.0
Charges related to legal settlement			3.3
Loss on bank amendment			1.3
Senior Credit Facility [Member]
Unusual or Infrequent Item [Line Items]
Loss on bank amendment			1.3
9.5% Senior Subordinated Notes [Member]
Unusual or Infrequent Item [Line Items]
Debt instrument, amount redeemed		75.0
Debt instrument, interest rate stated percentage		9.50%
Redemption price, principal amount		100.00%
Write-off deferred financing costs		0.4
2.25% Convertible Subordinated Debentures [Member]
Unusual or Infrequent Item [Line Items]
Debt instrument, interest rate stated percentage			2.25%
Debentures repurchased, principal amount			22.0
Loss on repurchase of debentures			$ 0.2
2.25% Convertible Subordinated Debentures [Member] | Minimum [Member]
Unusual or Infrequent Item [Line Items]
Debentures price range			99.00%
2.25% Convertible Subordinated Debentures [Member] | Maximum [Member]
Unusual or Infrequent Item [Line Items]
Debentures price range			99.60%