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, 2016	May 31, 2015	May 31, 2016	May 31, 2015
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	9,700	6,900	9,700	6,900
Numerator:
Net income	$ 15,597	$ 9,573	$ 28,724	$ 17,372
Less: Distributed earnings allocated to nonvested restricted stock	(10)	(8)	(21)	(16)
Less: Undistributed earnings allocated to nonvested restricted stock	(66)	(24)	(116)	(45)
Numerator for basic earnings per share	15,521	9,541	28,587	17,311
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	667	667	1,333	1,333
Add: Undistributed earnings allocated to nonvested restricted stock	66	24	116	45
Less: Undistributed earnings reallocated to nonvested restricted stock	(59)	(22)	(104)	(41)
Numerator for diluted earnings per share	$ 16,195	$ 10,210	$ 29,932	$ 18,648
Denominator:
Weighted average shares outstanding — basic	84,196	91,995	86,704	91,974
Effect of dilutive securities: Share-based payments	2,122	1,147	1,954	1,094
Effect of dilutive securities: Convertible senior notes	8,402	8,402	8,402	8,402
Weighted average shares outstanding — diluted	94,720	101,544	97,060	101,470
Basic earnings per share, in dollars per share	$ 0.18	$ 0.10	$ 0.33	$ 0.19
Diluted earnings per share, in dollars per share	$ 0.17	$ 0.10	$ 0.31	$ 0.18