Basis of Presentation and Significant Accounting Policies - Impact of ROU Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Apr. 30, 2020	Nov. 01, 2019	Oct. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 158.8	$ 167.5
Current portion of lease liabilities	36.0	36.3
Other accrued liabilities	158.6	155.2	$ 158.2
Long-term lease liabilities	144.8	154.2
Other noncurrent liabilities	$ 77.5	58.8	$ 78.8
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets		167.5
Current portion of lease liabilities		36.3
Other accrued liabilities		(3.0)
Long-term lease liabilities		154.2
Other noncurrent liabilities		$ (20.0)