General (Details) - USD ($) $ in Millions	Jul. 31, 2021	Apr. 30, 2021	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment upon adoption of accounting standards update	$ (6,785.4)	$ (6,162.8)	$ (5,989.9)	$ (3,824.8)	$ (3,760.4)	$ (3,627.5)	$ (3,730.9)	$ (3,628.6)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment upon adoption of accounting standards update	$ (6,091.8)	$ (5,477.5)	$ (5,360.0)	(3,261.8)	$ (3,180.6)	$ (3,126.9)	$ (3,115.4)	$ (3,026.4)
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment upon adoption of accounting standards update				1.4
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment upon adoption of accounting standards update				$ 1.4