Employee Benefit Plans (Tables)

6 Months Ended

Mar. 31, 2020

Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of Net Periodic Benefit Cost

Components of net periodic pension benefit cost were as follows (in millions):

	Three Months Ended March 31,						Six Months Ended March 31,
	2020			2019			2020			2019
Components of net periodic benefit cost
Service cost	$	2.6		$	2.4		$	5.1		$	4.8
Interest cost		4.3			4.7			8.6			9.4
Expected return on plan assets		(5.2	)		(5.0	)		(10.3	)		(10.0	)
Amortization of prior service cost (benefit)		0.4			0.5			0.8			0.9
Curtailment		—			1.2			—			1.2
Amortization of net actuarial loss (gain)		0.8			0.1			1.6			0.1
Expenses paid		1.0			0.6			2.0			1.2
Net periodic benefit cost	$	3.9		$	4.5		$	7.8		$	7.6

Components of net periodic other post-employment benefit cost were as follows (in millions):

	Three Months Ended March 31,						Six Months Ended March 31,
	2020			2019			2020			2019
Components of net periodic benefit cost
Service cost	$	0.8		$	0.7		$	1.7		$	1.5
Interest cost		0.4			0.5			0.8			1.0
Amortization of prior service cost (benefit)		(0.3	)		(0.3	)		(0.5	)		(0.7	)
Amortization of net actuarial loss (gain)		—			—			(0.1	)		(0.1	)
Net periodic benefit cost	$	0.9		$	0.9		$	1.9		$	1.7