Employee Benefit Plans (Tables)

12 Months Ended

Mar. 31, 2019

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The aggregate net pension expense relating to these two plans is as follows (in millions):

	Year Ended March 31,
	2019		2018		2017
Service costs	$	1.5	$	2.2	$	1.4
Interest costs	1.1		1.0		1.0
Amortization of actuarial loss	0.4		0.8		—
Settlements	—		—		0.5
Net pension period cost	$	3.0	$	4.0	$	2.9

Schedule of Changes in Projected Benefit Obligations

The change in projected benefit obligation and the accumulated benefit obligation, were as follows (in millions):

	Year Ended March 31,
	2019			2018
Projected benefit obligation at the beginning of the year	$	61.0		$	50.4
Additions due to acquisition of Microsemi	9.8			—
Service cost	1.5			2.2
Interest cost	1.1			1.0
Actuarial losses	6.0			0.7
Benefits paid	(0.9		)	(0.8		)
Foreign currency exchange rate changes	(5.8		)	7.5
Projected benefit obligation at the end of the year	$	72.7		$	61.0
Accumulated benefit obligation at the end of the year	$	66.7		$	55.5
Weighted average assumptions
Discount rate	1.41		%	1.73		%
Rate of compensation increase	2.79		%	2.91		%

Schedule of Assumptions Used

The change in projected benefit obligation and the accumulated benefit obligation, were as follows (in millions):

	Year Ended March 31,
	2019			2018
Projected benefit obligation at the beginning of the year	$	61.0		$	50.4
Additions due to acquisition of Microsemi	9.8			—
Service cost	1.5			2.2
Interest cost	1.1			1.0
Actuarial losses	6.0			0.7
Benefits paid	(0.9		)	(0.8		)
Foreign currency exchange rate changes	(5.8		)	7.5
Projected benefit obligation at the end of the year	$	72.7		$	61.0
Accumulated benefit obligation at the end of the year	$	66.7		$	55.5
Weighted average assumptions
Discount rate	1.41		%	1.73		%
Rate of compensation increase	2.79		%	2.91		%

Schedule of Expected Benefit Payments

Future estimated expected benefit payments for fiscal year 2020 through 2029 are as follows (in millions):

Fiscal Year Ending March 31,	Expected Benefit Payments
2020	$	1.3
2021	1.5
2022	1.9
2023	1.8
2024	2.3
2025 through 2029	11.9
Total	$	20.7