Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011
Reconciliation of change in gross unrecognized tax benefits
Balance, beginning of period	$ 101,047	$ 140,142	$ 104,669	$ 160,446
Increase in benefit as a result of tax positions taken in prior years		1,250	3,000	2,500
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions
Decrease in benefit as a result of resolution of uncertain tax positions	(1,223)		(3,723)	(17,954)
Decrease in benefit as a result of completion of tax audits			(4,122)	(3,600)
Balance, end of period	$ 99,824	$ 141,392	$ 99,824	$ 141,392