Employee Benefits (Tables)

3 Months Ended

9 Months Ended

Sep. 30, 2022

Sep. 30, 2022

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

Components of net periodic benefit cost for both the Retirement Plans and PBOP for the three months ended September 30, 2022 and 2021, were as follows (in millions):

	Retirement Plans				PBOP
	For the Three Months Ended September 30,				For the Three Months Ended September 30,
	2022		2021		2022		2021
Service cost	$	0.5	$	0.6	$	—	$	—
Interest cost	1.0		0.7		0.2		0.3
Expected return on plan assets	(1.1)		(1.6)		(0.4)		(0.7)
Amortization of unrecognized net loss	0.4		0.2		—		—
Settlement charge	0.5		0.6		—		—
Regulatory asset (increase) decrease	(0.6)		0.8		—		—
Net periodic benefit cost	$	0.7	$	1.3	$	(0.2)	$	(0.4)

Components of net periodic benefit cost for both the Retirement Plans and PBOP for the nine months ended September 30, 2022 and 2021, were as follows (in millions):

	Retirement Plans				PBOP
	For the Nine Months Ended September 30,				For the Nine Months Ended September 30,
	2022		2021		2022		2021
Service cost	$	1.8	$	2.0	$	—	$	—
Interest cost	2.1		1.6		0.6		0.7
Expected return on plan assets	(4.1)		(4.7)		(1.3)		(2.0)
Amortization of unrecognized net loss	0.4		0.8		—		—
Settlement charge	2.1		1.5		—		—
Regulatory asset decrease	0.9		0.8		—		—
Net periodic benefit cost	$	3.2	$	2.0	$	(0.7)	$	(1.3)