Employee Benefit and Stock Plans (Details Textual) (USD $)	12 Months Ended								12 Months Ended					12 Months Ended							12 Months Ended
	Nov. 30, 2011 Year Person	Nov. 30, 2010	Nov. 30, 2009	Oct. 06, 2011	Oct. 07, 2010	Apr. 01, 2010	Jan. 21, 2010	Jul. 12, 2007	Nov. 30, 2011 Saving Plan [Member]	Nov. 30, 2010 Saving Plan [Member]	Nov. 30, 2009 Saving Plan [Member]	Nov. 30, 2009 Maximum [Member]	Nov. 30, 2009 Minimum [Member]	Nov. 30, 2011 1988 Employee Stock Plan [Member]	Nov. 30, 2011 August 2010 Exchange Offer [Member] Person	Nov. 30, 2011 November 2010 Exchange Offer [Member] Person	Nov. 30, 2008 Phantom [Member]	Nov. 30, 2011 Phantom [Member]	Nov. 30, 2010 Phantom [Member]	Nov. 30, 2009 Phantom [Member]	Nov. 30, 2011 2010 Equity Incentive Plan [Member]	Apr. 07, 2011 2010 Equity Incentive Plan [Member]	Apr. 01, 2010 2010 Equity Incentive Plan [Member]	Nov. 30, 2011 Stock Appreciation Rights (SARs) [Member]	Nov. 30, 2010 Stock Appreciation Rights (SARs) [Member]	Nov. 30, 2009 Stock Appreciation Rights (SARs) [Member]
Employee Benefit and Stock Plans (Textual) [Abstract]
Aggregate cost related to saving plan									$ 2,800,000	$ 3,200,000	$ 3,200,000
Net assets invested in funds consisting common stock	4.00%	5.00%	6.00%
Number of shares authorized for issuance of stock based awards to employees																							3,500,000
Number of additional shares authorized for issuance of stock based awards to employees																						4,000,000
Grant of stock option, Reduce the plan share capacity						1
Share Based payments award terms of Award														15 years							10 years
Number of Employees to purchase Company's common stock in exchange for corresponding grants of stock options															18
Purchase price of common stock per share for 18 eligible employees															$ 19.90
Purchase price of common stock per share for 1 eligible employees															$ 11.25
Purchase price of common stock per share																$ 28.10
Purchase price of common stock per share for 7 eligible employees																$ 36.19
Shares purchase per employee															42,293	193,535
Number of eligible employees returned SARs related to the exchange offer to the company															19	9
SARs returned to the company															1,116,030	925,705
Common Stock Purchase by Employee															1,073,737	732,170
Performance shares vested and become unrestricted												150.00%	0.00%
Vesting period of vesting shares																	3 years
SARs vest in equal annual installments period																	3 years
Outstanding at end of year, Shares																		5,556	268,762	926,705				29,939	37,517	2,292,537
Number of employees to whom stock options granted in exchange for stock appreciation rights																7
Number of Employees to whom one grant of stock options to purchase Company's common stock	1
Employee Benefit and Stock Plan (Additional Textual) [Abstract]
Company's common stock at the purchase price per share				$ 6.32	$ 11.06
Grant-date fair value per performance-based stock option				$ 2.54	$ 4.59
Weighted average fair value of stock options granted	$ 2.56	$ 2.81	$ 7.16
Stock-based compensation expense related to stock option grants	5,900,000	5,800,000	2,600,000
Total unrecognized stock-based compensation expense related to unvested stock option awards	5,700,000
Expense expected to be recognized over a weighted average period	1.6
Tax benefits from stock-based compensation	0	583,000	0
Relinquished of restricted common stock to the company by former chairman and chief executive officer		0
Performance shares awarded to president and chief executive officer subject to term plans								54,000
Intrinsic value of stock options exercisable	0	100,000	100,000
Intrinsic value of stock options outstanding	1,700,000	300,000	100,000
Grant of restricted stock, Reduce the Plan share capacity						$ 1.78
Period for shareholder return			3 years
Relinquished of stock options to the company by former chairman and chief executive officer			3,011,452
Intrinsic value of stock option exercised	0	100,000	0
Total grant-date fair value of performance shares recognized over the service period			0					2,000,000
Performance-based stock options to purchase an aggregate shares of company's common stock				365,000	260,000
Performance shares vesting restrictions lapsed							48,492
Recognized compensation expense related to various stock	1,200,000	700,000	8,900,000
Shares of common stock held in trust	10,884,151	11,082,723
Minimum period of restriction imposed on share grant lapse	3 years
Maximum period of restriction imposed on share grant lapse	8 years
Common stock market price				$ 0.00
Value per performance based stock option				$ 0.00
Tax shortfall from cancellation of stock awards	$ 1,000,000	$ 2,800,000	$ 4,100,000