Pensions and Other Postretirement Benefits

6 Months Ended

Oct. 31, 2019

Retirement Benefits [Abstract]

Pensions and Other Postretirement Benefits

The components of our net periodic benefit cost for defined benefit pension and other postretirement benefit plans are shown below.

	Three Months Ended October 31,
	Defined Benefit Pension Plans						Other Postretirement Benefits
	2019			2018			2019			2018
Service cost	$	0.4		$	0.5		$	0.4		$	0.5
Interest cost	5.3			5.8			0.6			0.6
Expected return on plan assets	(6.1		)	(6.7		)	—			—
Amortization of net actuarial loss (gain)	2.0			2.1			—			(0.2		)
Amortization of prior service cost (credit)	0.2			0.3			(0.3		)	(0.3		)
Net periodic benefit cost	$	1.8		$	2.0		$	0.7		$	0.6

	Six Months Ended October 31,
	Defined Benefit Pension Plans						Other Postretirement Benefits
	2019			2018			2019			2018
Service cost	$	0.8		$	1.1		$	0.9		$	0.9
Interest cost	10.5			11.7			1.2			1.2
Expected return on plan assets	(12.1		)	(13.5		)	—			—
Amortization of net actuarial loss (gain)	4.0			4.1			(0.1		)	(0.3		)
Amortization of prior service cost (credit)	0.4			0.5			(0.6		)	(0.6		)
Net periodic benefit cost	$	3.6		$	3.9		$	1.4		$	1.2