Segment and Geographic Information - Summary of Revenues by Geographic Region (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2014		Oct. 31, 2013		Oct. 31, 2012
Geographic Information [Line Items]
Revenues	$ 1,298.9	$ 1,276.1	$ 1,231.3	$ 1,226.5	$ 1,236.8	$ 1,216.8	$ 1,173.6	$ 1,182.1	$ 5,032.8	[1]	$ 4,809.3	[1]	$ 4,300.3	[1]
Domestic country
Geographic Information [Line Items]
Revenues									4,902.5	[1]	4,703.0	[1]	4,243.0	[1]
All other countries
Geographic Information [Line Items]
Revenues									$ 130.3	[1]	$ 106.3	[1]	$ 57.3	[1]

[1] Substantially all of our long-lived assets are related to United States operations.