Nature Of Business And Summary Of Significant Accounting Policies (Correction of Prior Period Amounts (Stockholders' Equity)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009
Retained Earnings (Accumulated Deficit) [Abstract]
Retained earnings				$ 327,542				$ 350,409	$ 327,542	$ 350,409	$ 312,588
Net income	36,025	5,838	(1,908)	7,489	12,175	9,059	17,919	20,476	47,444	59,629	48,098
Retained earnings	348,830				327,542				348,830	327,542	350,409
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive loss	(10,764)				(11,653)				(10,764)	(11,653)	(7,739)	(1,986)
Total shareholders' equity	638,399				625,110				638,399	625,110	690,273	557,867
As Previously Reported [Member]
Retained Earnings (Accumulated Deficit) [Abstract]
Retained earnings								349,870		349,870	311,576
Net income					11,679	8,601	17,960	20,521		58,761	48,571
Retained earnings					326,135					326,135	349,870
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive loss					(13,056)					(13,056)	(9,142)	(3,389)
Total shareholders' equity					622,300					622,300	688,331	555,452
Adjustment [Member]
Retained Earnings (Accumulated Deficit) [Abstract]
Retained earnings								539		539	1,012
Net income					496	458	(41)	(45)		868	(473)
Retained earnings					1,407					1,407	539
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive loss					1,403					1,403	1,403	1,403
Total shareholders' equity					$ 2,810					$ 2,810	$ 1,942	$ 2,415