Earnings Per Share (Basic and Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Debt Instrument [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	1,600	3,600		3,600
Numerator:
Net income (loss)	$ 57,308	$ 31,782	$ (13,947)	$ 46,041
Less: Distributed earnings allocated to nonvested restricted stock	(12)	(14)	0	(29)
Less: Undistributed earnings allocated to nonvested restricted stock	(310)	(200)	0	(285)
Numerator for basic earnings (loss) per share	56,986	31,568	(13,947)	45,727
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	796	664	0	1,327
Add: Undistributed earnings allocated to nonvested restricted stock	310	200	0	285
Less: Undistributed earnings reallocated to nonvested restricted stock	(269)	(175)	0	(251)
Numerator for diluted earnings (loss) per share	$ 57,823	$ 32,257	$ (13,947)	$ 47,088
Denominator:
Weighted average shares outstanding — basic (in shares)	87,581	85,445	87,370	85,285
Effect of dilutive securities: Share-based payments (in shares)	5,176	3,885	0	3,288
Effect of dilutive securities: Convertible senior notes (in shares)	8,402	8,402	0	8,402
Weighted average shares outstanding — diluted (in shares)	101,159	97,732	87,370	96,975
Basic earnings per share (in dollars per share)	$ 0.65	$ 0.37	$ (0.16)	$ 0.54
Diluted earnings per share (in dollars per share)	$ 0.57	$ 0.33	$ (0.16)	$ 0.49