CONVERTIBLE SENIOR NOTES (Details) (USD $)	3 Months Ended		6 Months Ended			1 Months Ended	3 Months Ended	6 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013	Nov. 30, 2013	Apr. 30, 2012 Convertible Debt	May 31, 2014 Convertible Debt	May 31, 2014 Convertible Debt	May 31, 2013 Convertible Debt	May 31, 2014 Significant other Observable Inputs (Level 2)
Debt Instrument [Line Items]
Principal amount of senior note						$ 600,000,000.0	$ 600,000,000	$ 600,000,000
Debt instrument, fixed annual interest rate						2.25%
Principal amount of note						1,000	1,000	1,000
Convertible senior notes conversion ratio (shares)						19.7750
Convertible senior notes initial conversion price (in dollars per share)						$ 50.57
Convertible senior notes minimum number of days out of thirty consecutive trading days that common stock price exceeded conversion price								20 days
Convertible senior notes number of consecutive trading days								30 days
Convertible senior notes minimum percentage of conversion price							130.00%	130.00%
Consecutive trading day period								5 days
Convertible senior notes maximum percentage of trading price							98.00%	98.00%
Stock observation period								35 days
Debt effective interest rate									5.50%
Debt discount, before tax						84,600,000	51,900,000	51,900,000
Debt discount, after tax						52,600,000
Convertible senior notes, net	548,123,000		548,123,000		540,022,000		548,100,000	548,100,000
Deferred issuance costs						15,600,000
Deferred issuance costs, liability component						13,400,000
Deferred issuance costs, equity component						2,200,000
Deferred issuance costs, equity component net of tax						1,400,000
Interest expense	8,566,000	8,663,000	17,086,000	17,445,000			8,100,000
Loan origination fees and issuance costs							3,300,000	3,400,000
Amortization of debt discount							4,100,000
Amortization of debt issuance costs							700,000
Convertible senior notes, fair value disclosures										$ 608,100,000