Other Matters - Additional Information (Detail) (USD $) In Millions, unless otherwise specified						12 Months Ended
	Oct. 31, 2012	Feb. 28, 2012 Former Employees Employee	Feb. 28, 2012 Current and Former Employees Employee	Oct. 31, 2012 Minimum	Oct. 31, 2012 Maximum	Oct. 31, 2012 Property Subject to Operating Lease	Oct. 31, 2011 Property Subject to Operating Lease	Oct. 31, 2010 Property Subject to Operating Lease
Commitments and Contingencies Disclosure [Line Items]
Operating leases, expiration year						2017
Operating leases, rental expense						$ 6.8	$ 7.7	$ 7.7
Contractual obligations to purchase for feed grains, feed ingredients, and packaging supplies	318
Contractual obligations to purchase for feed grains, feed ingredients, and packaging supplies, due in less than one year	$ 315.4
Contractual obligations to purchase for feed grains, feed ingredients, and packaging supplies, terms of the remaining amount				1 year	3 years
Number of employees who filled for damage claims		2	7