Long-term Debt - Summary of Long-term Debt (Detail) (USD $) In Millions, unless otherwise specified	May 31, 2014	Nov. 30, 2013
Debt Instrument [Line Items]
Term loan, bearing interest at variable rates (rate of 2.48% as of May 31, 2014), payable in quarterly installments of $1.3 million plus interest, maturing in May 2019	$ 96.3	$ 42.5
Total senior debt	100.0	45.0
Total senior secured notes	460.0	460.0
Convertible subordinated debentures, bearing interest at 4.0625% per annum, interest payments due in June and December, maturing in December 2039	143.0	193.2
Total convertible subordinated notes	143.2	193.4
Capital lease, payable in monthly installments, maturing in March 2017	0.8	0.8
Total other debt	79.8	0.8
Total debt	783.0	699.2
Less: Amounts due within one year	(4.2)	(2.9)
Total long-term debt	778.8	696.3
Total debt	783.0	699.2
Term Loan Due on 2019 [Member]
Debt Instrument [Line Items]
Term loan, bearing interest at variable rates (rate of 2.48% as of May 31, 2014), payable in quarterly installments of $1.3 million plus interest, maturing in May 2019	100.0	45.0
Senior subordinated notes [Member]
Debt Instrument [Line Items]
Total senior secured notes	460.0	460.0
Convertible Subordinated Debentures, Bearing Interest at 2.25% Maturing in November 2024 [Member]
Debt Instrument [Line Items]
Convertible subordinated debentures, bearing interest at 2.25% per annum, interest payments due in May and November, maturing in November 2024	0.2	0.2
Convertible Subordinated Debentures, Bearing Interest at 4.0625% Maturing in December 2039 [Member]
Debt Instrument [Line Items]
Convertible subordinated debentures, bearing interest at 4.0625% per annum, interest payments due in June and December, maturing in December 2039	143.0	193.2
Delayed Draw Term Loan [Member]
Debt Instrument [Line Items]
Delayed draw term loan, bearing interest at variable rates (rate of 9.50% as of May 31, 2014), maturing in April 2022	79.0	0
Total debt	79.0	0
Total debt	$ 79.0	$ 0