Basis of Presentation and Significant Accounting Policies (Basic and Diluted Earnings (Loss) Per Share) (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012
Numerator:
Net income (loss)	$ 27,278,000	$ 3,261,000	$ 11,847,000	$ (66,677,000)
Participating Securities, Distributed and Undistributed Earnings	(6,000)	(8,000)	(18,000)	0
Undistributed Earnings Allocated to Participating Securities	(73,000)	(5,000)	(16,000)	0
Net Income (Loss) Available to Common Stockholders, Basic	27,199,000	3,248,000	11,813,000	(66,677,000)
Interest on Convertible Debt, Net of Tax	667,000	0	0	0
Undistributed Earnings Reallocated To Participating Securities	(65,000)	(4,000)	(14,000)	0
Net Income (Loss) Available to Common Stockholders, Diluted	$ 27,874,000	$ 3,249,000	$ 11,815,000	$ (66,677,000)
Denominator:
Weighted Average Number of Shares Outstanding, Basic	83,714	77,127	82,261	77,107
Incremental Common Shares Attributable to Share-based Payment Arrangements	1,931	231	2,028	0
Incremental Common Shares Attributable to Conversion of Debt Securities	8,402	0	0	0
Weighted Average Number of Shares Outstanding, Diluted	94,047	77,358	84,289	77,107
Earnings Per Share, Basic, in dollars per share	$ 0.32	$ 0.04	$ 0.14	$ (0.86)
Earnings Per Share, Diluted, in dollars per share	$ 0.30	$ 0.04	$ 0.14	$ (0.86)