Employee Benefits - Schedule of Components of Net Periodic Defined Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2020	Jan. 31, 2019
Retirement Benefits [Abstract]
Service cost	$ 3.5	$ 2.5
Interest cost	1.2	1.5
Expected return on plan assets	(2.7)	(2.4)
Recognized net actuarial loss	1.0	0.2
Net periodic defined benefit plan cost	$ 3.0	$ 1.8