Earnings Per Share (Basic and Diluted Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Feb. 28, 2015	Feb. 28, 2014
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	8,200,000	5,200,000
Numerator:
Net income	$ 7,799	$ 10,563
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic	9	5
Less: Undistributed earnings allocated to nonvested restricted stock	(20)	(22)
Numerator for basic earnings per share	7,770	10,536
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	667	667
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	20	22
Less: Undistributed earnings reallocated to nonvested restricted stock	(18)	(20)
Numerator for diluted earnings per share	$ 8,439	$ 11,205
Denominator:
Weighted Average Number of Shares Outstanding, Basic	91,954,000	83,745,000
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,344,000	1,799,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	8,402,000	8,402,000
Weighted Average Number of Shares Outstanding, Diluted	101,700,000	93,946,000
Earnings Per Share, Basic, in dollars per share	$ 0.08	$ 0.13
Earnings Per Share, Diluted, in dollars per share	$ 0.08	$ 0.12