EMPLOYEE BENEFITS (Tables)

6 Months Ended

Jun. 30, 2024

Retirement Benefits [Abstract]

Schedule of net benefit cost (credit)

The following tables show the components of net periodic benefit cost (credit) (including amounts capitalized to our balance sheets) for our benefit plans.

	Pension Benefits
	Three Months Ended June 30				Six Months Ended June 30
(in millions)	2024		2023		2024		2023
Service cost	$	1.2	$	1.0	$	2.5	$	2.4
Interest cost	7.3		7.6		14.7		15.1
Expected return on plan assets	(12.8)		(12.8)		(25.5)		(25.7)
Amortization of net actuarial loss	4.3		4.5		8.6		8.7
Net periodic benefit cost	$	—	$	0.3	$	0.3	$	0.5

	OPEB Benefits
	Three Months Ended June 30				Six Months Ended June 30
(in millions)	2024		2023		2024		2023
Service cost	$	0.7	$	0.7	$	1.5	$	1.4
Interest cost	1.7		1.6		3.3		3.1
Expected return on plan assets	(4.4)		(4.1)		(8.7)		(8.2)
Amortization of prior service credit	(2.6)		(2.6)		(5.1)		(5.1)
Amortization of net actuarial loss	0.7		0.3		1.2		0.5
Net periodic benefit credit	$	(3.9)	$	(4.1)	$	(7.8)	$	(8.3)