Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 120.1	$ 100.8	$ 345.7	$ 39.2
Other comprehensive loss:
Foreign currency translation adjustment, net of tax	(65.2)	(69.6)	(51.1)	(10.3)
Comprehensive income	$ 54.9	$ 31.2	$ 294.6	$ 28.9