Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Class A Common Stock, $.01 par value, 80,000,000 shares authorized; 26,081,558 and 26,182,518 issued and outstanding in 2012 and 2013, respectively	Class B Common Stock, $.01 par value, 40,000,000 shares authorized; 20,050,277 and 19,994,663 issued and outstanding in 2012 and 2013, respectively	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning Balance at Nov. 30, 2010	$ 1,187,177	$ 275	$ 203	$ 481,154	$ 712,099	$ (6,554)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	69,424				69,424
Other comprehensive income	613					613
Exercise of stock options	51			51
Cash dividends ($.16 per share for 2010, $.18 per share for 2011 and $.20 per share for 2012)	(8,585)				(8,585)
Reacquisition of previously issued common stock	(37,404)	(14)		(37,390)	0
Conversion of Class B Common Stock to Class A Common Stock	0	3	(3)
Other	(276)			(276)
Stock-based compensation	1,466			1,466
Ending Balance at Nov. 30, 2011	1,212,466	264	200	445,005	772,938	(5,941)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	54,578				54,578
Other comprehensive income	645					645
Cash dividends ($.16 per share for 2010, $.18 per share for 2011 and $.20 per share for 2012)	(9,283)				(9,283)
Reacquisition of previously issued common stock	(10,556)	(4)		(3,491)	(7,061)
Other	(914)			(914)
Stock-based compensation	1,874			1,874
Ending Balance at Nov. 30, 2012	1,248,810	260	200	442,474	811,172	(5,296)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	45,292				45,292
Other comprehensive income	658					658
Exercise of stock options	341	1		340
Cash dividends ($.16 per share for 2010, $.18 per share for 2011 and $.20 per share for 2012)	(10,229)				(10,229)
Reacquisition of previously issued common stock	(259)	0		(259)	0
Other	9			9
Stock-based compensation	2,533			2,533
Ending Balance at Nov. 30, 2013	$ 1,287,155	$ 261	$ 200	$ 445,097	$ 846,235	$ (4,638)