Earnings Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011
Earnings Per Share Reconciliation Of Basic And Diluted
Net Income	$ (5,003,000)	$ (2,293,000)	$ 55,790,000	$ 85,923,000	$ (1,959,000)	$ (4,613,000)	$ 50,192,000	$ 76,227,000	$ 134,417,000	$ 119,847,000	$ 113,568,000
Average shares of common stock outstanding for basic earnings per share									74,884,000	71,977,000	72,056,000
Contingently issuable shares under incentive compensation plans									289,000	301,000	210,000
Contingently issuable shares under forward sale agreements									160,000	0	0
Average shares of dilutive stock									75,333,000	72,278,000	72,266,000
Earnings Per Share of Common Stock
Basic EPS	$ (0.07)	$ (0.03)	$ 0.74	$ 1.19	$ (0.03)	$ (0.06)	$ 0.70	$ 1.06	$ 1.80	$ 1.67	$ 1.58
Diluted EPS	$ (0.07)	$ (0.03)	$ 0.74	$ 1.18	$ (0.03)	$ (0.06)	$ 0.70	$ 1.05	$ 1.78	$ 1.66	$ 1.57