Financial Instruments and Fair Value Measurements - Estimated Fair Values for the Company's Senior Notes and Assets Held by Special Purpose Entities (Details) - Estimate of Fair Value Measurement - USD ($) $ in Millions	Oct. 31, 2019	Oct. 31, 2018
Estimated Fair Value Of Financial Instruments [Line Items]
Assets held by special purpose entities estimated fair value	$ 51.9	$ 51.6
Senior Notes due 2019
Estimated Fair Value Of Financial Instruments [Line Items]
Estimated fair value of debt instruments	0.0	257.4
Senior Notes due 2021
Estimated Fair Value Of Financial Instruments [Line Items]
Estimated fair value of debt instruments	248.1	263.4
Senior Notes due 2027
Estimated Fair Value Of Financial Instruments [Line Items]
Estimated fair value of debt instruments	$ 537.9	$ 0.0