Earnings (Loss) Per Share (Basic and Diluted Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Numerator:
Net income (loss)	$ 26,624	$ (2,973)	$ 37,187	$ (15,431)
Less: Distributed earnings allocated to nonvested restricted stock	(6)	0	(12)	0
Less: Undistributed earnings allocated to nonvested restricted stock	(66)	0	(88)	0
Numerator for basic earnings (loss) per share	26,552	(2,973)	37,087	(15,431)
Interest expense and amortization of debt issuance costs associated with convertible senior notes, net of taxes	667	0	1,333	0
Add: Undistributed earnings allocated to nonvested restricted stock	66	0	88	0
Less: Undistributed earnings reallocated to nonvested restricted stock	(59)	0	(80)	0
Numerator for diluted earnings (loss) per share	$ 27,226	$ (2,973)	$ 38,428	$ (15,431)
Denominator:
Weighted Average Number of Shares Outstanding, Basic	89,529	83,605	86,668	81,526
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,577	0	1,689	0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	8,402	0	8,402	0
Weighted Average Number of Shares Outstanding, Diluted	99,508	83,605	96,759	81,526
Earnings Per Share, Basic, in dollars per share	$ 0.30	$ (0.04)	$ 0.43	$ (0.19)
Earnings Per Share, Diluted, in dollars per share	$ 0.27	$ (0.04)	$ 0.40	$ (0.19)