Earnings Per Share (Basic and Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Feb. 28, 2018	Feb. 28, 2017
Debt Instrument [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)		5,100
Numerator:
Net income (loss)	$ (71,255)	$ 14,259
Less: Distributed earnings allocated to nonvested restricted stock	0	(15)
Less: Undistributed earnings allocated to nonvested restricted stock	0	(85)
Numerator for basic earnings (loss) per share	(71,255)	14,159
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	0	663
Add: Undistributed earnings allocated to nonvested restricted stock	0	85
Less: Undistributed earnings reallocated to nonvested restricted stock	0	(75)
Numerator for diluted earnings (loss) per share	$ (71,255)	$ 14,832
Denominator:
Weighted average shares outstanding — basic (in shares)	87,155	85,122
Effect of dilutive securities: Share-based payments (in shares)	0	2,749
Effect of dilutive securities: Convertible senior notes (in shares)	0	8,402
Weighted average shares outstanding — diluted (in shares)	87,155	96,273
Basic earnings per share (in dollars per share)	$ (0.82)	$ 0.17
Diluted earnings per share (in dollars per share)	$ (0.82)	$ 0.15