CONVERTIBLE SENIOR NOTES (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended			1 Months Ended	3 Months Ended	27 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Nov. 30, 2013	Apr. 30, 2012 Convertible Debt	Feb. 28, 2014 Convertible Debt	Feb. 28, 2014 Convertible Debt	Feb. 28, 2013 Convertible Debt	Feb. 28, 2014 Fair Value, Inputs, Level 2
Debt Disclosure [Line Items]
Principal amount of senior note				$ 600,000,000	$ 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
Payments classification for shares repurchased	35,799,000	21,871,000		121,000,000
Shares repurchased (in shares)	1.6			3.6
Debt effective interest rate							5.50%
Debt discount, before tax				84,600,000	55,900,000	55,900,000
Debt discount, after tax				52,600,000
Convertible senior notes, net	544,054,000		540,022,000		544,100,000	544,100,000
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	8,520,000	8,782,000			8,100,000
Loan origination fees and issuance costs					3,400,000	3,400,000
Amortization of debt discount					4,000,000
Amortization of debt issuance costs					700,000
Convertible senior notes, fair value disclosures								$ 609,000,000