Significant accounting policies (Details)	12 Months Ended
	Oct. 31, 2011 Year
Land Improvements [Member]
Useful lives of property, plant and equipment and depreciation
Useful Life Minimum	15
Useful Life Maximum	25
Buildings [Member]
Useful lives of property, plant and equipment and depreciation
Useful Life Minimum	20
Useful Life Maximum	40
Machinery and equipment [Member]
Useful lives of property, plant and equipment and depreciation
Useful Life Minimum	3
Useful Life Maximum	12
Enterprise management systems [Member]
Useful lives of property, plant and equipment and depreciation
Useful Life Minimum	5
Useful Life Maximum	13