Business Combinations (Details) - USD ($) $ in Thousands	6 Months Ended
	Apr. 30, 2016	Oct. 31, 2015	[1]
Business Acquisition [Line Items]
Goodwill	$ 2,500,804	$ 2,471,241
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	40,400
Goodwill	27,200
Business Acquisition, Goodwill, Expected Tax Deductible Amount	6,100
Identifiable Intangible Assets Acquired	16,900
Acquisition-Related Costs	$ 2,000
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

[1] Derived from audited financial statements.