Employee Benefits - Schedule of Components of Net Periodic Defined Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Retirement Benefits [Abstract]
Service cost	$ 5.2	$ 2.2	$ 12.1	$ 7.6
Interest cost	0.9	2.1	3.5	4.6
Expected return on plan assets	(3.6)	(2.8)	(9.0)	(7.4)
Recognized net actuarial gain (loss)	1.8	(0.2)	3.8	0.6
Net periodic defined benefit plan cost	$ 4.3	$ 1.3	$ 10.4	$ 5.4