Earnings (Loss) Per Share (Basic and Diluted Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,200,000	5,200,000	5,200,000	5,200,000
Numerator:
Net income	$ 28,361	$ 27,278	$ 65,548	$ 11,847
Less: Distributed earnings allocated to nonvested restricted stock	(6)	(6)	(18)	(18)
Less: Undistributed earnings allocated to nonvested restricted stock	(73)	(73)	(159)	(16)
Numerator for basic earnings per share	28,282	27,199	65,371	11,813
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	667	667	2,000	0
Add: Undistributed earnings allocated to nonvested restricted stock	73	73	159	16
Less: Undistributed earnings reallocated to nonvested restricted stock	(66)	(65)	(142)	(14)
Numerator for diluted earnings per share	$ 28,956	$ 27,874	$ 67,388	$ 11,815
Denominator:
Weighted Average Number of Shares Outstanding, Basic	91,793,000	83,714,000	88,389,000	82,261,000
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,875,000	1,931,000	1,823,000	2,028,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	8,402,000	8,402,000	8,402,000	0
Weighted Average Number of Shares Outstanding, Diluted	102,070,000	94,047,000	98,614,000	84,289,000
Earnings Per Share, Basic, in dollars per share	$ 0.31	$ 0.32	$ 0.74	$ 0.14
Earnings Per Share, Diluted, in dollars per share	$ 0.28	$ 0.30	$ 0.68	$ 0.14