Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2017	Aug. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 1,723,145
Net income	$ 50,208	$ 39,363	96,249	$ 68,087
Dividends on common stock			$ (6,479)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			1,204,676
Stock Issued During Period, Value, Stock Options Exercised			$ 20,677
Stock Issued During Period, Value, Share-based Compensation, Gross			0
Stock-based compensation			9,893
Stock repurchases			(2,543)
Ending balance	$ 1,840,942		$ 1,840,942
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding (in shares)			(116,224,000)
Beginning balance			$ 116,224
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			1,205,000
Stock Issued During Period, Value, Stock Options Exercised			$ 1,205
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			69,000
Stock Issued During Period, Value, Share-based Compensation, Gross			$ 69
Common Stock, Shares, Outstanding (in shares)	(117,498,000)		(117,498,000)
Ending balance	$ 117,498		$ 117,498
Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			696,938
Stock Issued During Period, Value, Stock Options Exercised			19,472
Stock Issued During Period, Value, Share-based Compensation, Gross			(3,767)
Stock-based compensation			9,893
Ending balance	722,536		722,536
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			1,563,742
Net income			96,249
Dividends on common stock			(6,479)
Ending balance	1,653,512		1,653,512
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(16,057)
Ending balance	$ (16,057)		$ (16,057)
Grantor Stock Ownership Trust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding (in shares)			(9,432,000)
Beginning balance			$ (102,300)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			279,000
Stock Issued During Period, Value, Share-based Compensation, Gross			$ 3,021
Common Stock, Shares, Outstanding (in shares)	(9,153,000)		(9,153,000)
Ending balance	$ (99,279)		$ (99,279)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding (in shares)			(21,720,000)
Beginning balance			$ (535,402)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			27,000
Stock Issued During Period, Value, Share-based Compensation, Gross			$ 677
Stock repurchases			$ (2,543)
Treasury Stock, Shares, Acquired (in shares)			(152,000)
Common Stock, Shares, Outstanding (in shares)	(21,845,000)		(21,845,000)
Ending balance	$ (537,268)		$ (537,268)