Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 100.8	$ 103.6	$ 39.2	$ 284.3
Other comprehensive (loss) income:
Foreign currency translation adjustment	(69.7)	38.3	(10.3)	104.8
Comprehensive income	$ 31.1	$ 141.9	$ 28.9	$ 389.1