Business Segment Information - Net Sales to External Customers by Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Net sales:
Total net sales	$ 867.6	$ 845.0	$ 839.6	$ 771.4	$ 868.5	$ 930.0	$ 915.9	$ 902.3	$ 3,323.6	$ 3,616.7	$ 4,239.1
United States
Net sales:
Total net sales									1,610.8	1,688.3	1,905.8
Europe, Middle East, and Africa
Net sales:
Total net sales									1,208.4	1,287.2	1,596.2
Asia Pacific and other Americas
Net sales:
Total net sales									$ 504.4	$ 641.2	$ 737.1