Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension benefit
Components of net periodic benefit cost
Service cost	$ 3.3	$ 2.9
Interest cost	4.4	4.6
Expected return on plan assets	(4.5)	(4.5)
Amortization of prior service cost	0.4	0.4
Amortization of net actuarial loss	1.0	0.6
Net periodic benefit cost	4.6	4.0
Other post-employment benefit
Components of net periodic benefit cost
Service cost	0.6	0.3
Interest cost	0.4	0.4
Amortization of prior service cost	(0.2)	(0.2)
Amortization of net actuarial loss	0.1	0.0
Net periodic benefit cost	0.9	0.5
Company contributions to fund benefit payments	0.5	$ 0.5
Defined benefit pension plans estimated future employer contributions in fiscal year	$ 1.6