Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2015	Aug. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 1,595,910
Net income	$ 23,254	$ 28,361	40,626	$ 65,548
Dividends on common stock			(6,890)
Employee stock options/other			436
Restricted stock awards			0
Stock-based compensation			10,444
Stock repurchases			(300)
Ending balance	1,640,226		1,640,226
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			115,387
Employee stock options/other			52
Restricted stock awards			85
Ending balance	115,524		115,524
Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			668,857
Employee stock options/other			384
Restricted stock awards			(85)
Stock-based compensation			10,444
Ending balance	679,600		679,600
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			1,391,256
Net income			40,626
Dividends on common stock			(6,890)
Ending balance	1,424,992		1,424,992
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(21,008)
Ending balance	(21,008)		(21,008)
Trust for Benefit of Employees [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(112,106)
Ending balance	(112,106)		(112,106)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(446,476)
Stock repurchases			(300)
Ending balance	$ (446,776)		$ (446,776)