EMPLOYEE BENEFITS (Tables)

6 Months Ended

Jun. 30, 2023

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)	2023		2022		2023		2022
Service cost	$	5.4	$	14.2	$	12.0	$	26.6
Interest cost	30.4		22.4		61.2		45.2
Expected return on plan assets	(46.4)		(52.5)		(93.8)		(105.2)
Loss on plan settlement	—		2.2		—		2.2
Amortization of prior service cost	—		0.4		0.1		0.8
Amortization of net actuarial loss	9.3		19.1		16.7		38.2
Net periodic benefit cost (credit)	$	(1.3)	$	5.8	$	(3.8)	$	7.8

	OPEB Benefits
	Three Months Ended June 30				Six Months Ended June 30
(in millions)	2023		2022		2023		2022
Service cost	$	2.4	$	3.3	$	4.9	$	7.1
Interest cost	5.4		3.8		10.8		7.7
Expected return on plan assets	(13.2)		(17.3)		(26.5)		(34.5)
Amortization of prior service credit	(3.7)		(3.9)		(7.4)		(7.9)
Amortization of net actuarial gain	(3.0)		(6.3)		(6.2)		(12.3)
Net periodic benefit credit	$	(12.1)	$	(20.4)	$	(24.4)	$	(39.9)