Fair Value Measures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Oct. 31, 2014
Fair Value Measures [Line Items]
Other-than-temporary impairment	$ 0	$ 0
Non-marketable equity securities	10.6		10.9
Cost Method Investments
Fair Value Measures [Line Items]
Non-marketable equity securities	6.7		6.7
Equity Method Investments
Fair Value Measures [Line Items]
Non-marketable equity securities	$ 3.9		$ 4.2