Restructuring Charges (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011	Oct. 31, 2011
Restructuring and Related Cost (Textual) [Abstract]
Restructuring charges	$ 10.1	$ 5.0	$ 19.0	$ 8.0
Restructuring cost incurred			32.5		10.4
Employee separation costs [Member]
Restructuring and Related Cost (Textual) [Abstract]
Restructuring charges			8.2
Restructuring cost incurred	3.0
Asset impairments [Member]
Restructuring and Related Cost (Textual) [Abstract]
Restructuring charges			4.9
Restructuring cost incurred	3.2
Other restructuring costs [Member]
Restructuring and Related Cost (Textual) [Abstract]
Restructuring charges			5.9
Restructuring cost incurred	$ 3.9