Long-term Debt - Additional Information - Convertible Subordinated Debentures (Detail) (USD $) In Millions, unless otherwise specified					6 Months Ended		0 Months Ended
	May 31, 2014	Nov. 30, 2013	May 31, 2014 Convertible Subordinated Debentures, Bearing Interest at 4.0625% Maturing in December 2039 [Member]	May 31, 2013 Convertible Subordinated Debentures, Bearing Interest at 4.0625% Maturing in December 2039 [Member]	May 31, 2014 Convertible Subordinated Debentures, Bearing Interest at 4.0625% Maturing in December 2039 [Member] Minimum [Member]	May 31, 2014 Convertible Subordinated Debentures, Bearing Interest at 4.0625% Maturing in December 2039 [Member] Maximum [Member]	May 31, 2014 4.0625% Debentures [Member]	May 31, 2014 4.0625% Debentures [Member]	Nov. 30, 2013 4.0625% Debentures [Member]
Debt Instrument [Line Items]
Debentures repurchased, principal amount			$ 50.2
Debentures price range					195.00%	212.00%
Debt instrument, interest rate stated percentage			4.0625%	4.0625%				4.0625%
Convertible subordinated notes	$ 783.0	$ 699.2						$ 143.0	$ 193.2
Convertible debentures into shares of common stock							15,900,000