Business Combinations (Details) - USD ($) $ in Thousands	6 Months Ended
	Apr. 30, 2017	Oct. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 2,661,538	$ 2,518,245
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Purchase Consideration, Net of Cash Acquired	188,100
Fair Value Of Stock Options Assumed	4,400
Goodwill	132,900
Goodwill, Expected Tax Deductible Amount	11,900
Identifiable Intangible Assets Acquired	64,900
Acquisition-Related Costs	$ 3,900
Series of Individually Immaterial Business Acquisitions | Minimum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Series of Individually Immaterial Business Acquisitions | Maximum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years