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, 2017	Feb. 29, 2016
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	5,100	9,700
Numerator:
Net income	$ 14,259	$ 13,127
Less: Distributed earnings allocated to nonvested restricted stock	(15)	(10)
Less: Undistributed earnings allocated to nonvested restricted stock	(85)	(50)
Numerator for basic earnings per share	14,159	13,067
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	663	667
Add: Undistributed earnings allocated to nonvested restricted stock	85	50
Less: Undistributed earnings reallocated to nonvested restricted stock	(75)	(45)
Numerator for diluted earnings per share	$ 14,832	$ 13,739
Denominator:
Weighted average shares outstanding — basic (in shares)	85,122	89,239
Effect of dilutive securities: Share-based payments (in shares)	2,749	1,786
Effect of dilutive securities: Convertible senior notes (in shares)	8,402	8,402
Weighted average shares outstanding — diluted (in shares)	96,273	99,427
Basic earnings per share (in dollars per share)	$ 0.17	$ 0.15
Diluted earnings per share (in dollars per share)	$ 0.15	$ 0.14