Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Reconciliation of Changes in Benefit Obligations, Funded Status and Amounts Recognized in Consolidated Balance Sheets

The following table provides a reconciliation of the changes in the benefit obligations, funded status and amounts recognized in the Consolidated Balance Sheets for the years ended December 31, 2023 and 2022 (dollars in millions):

	Pension Plans						Post-retirement Benefits
	Year ended December 31, 2023			Year ended December 31, 2022			Year ended December 31, 2023			Year ended December 31, 2022
Benefit Obligations:
Benefit obligation at beginning of year	$	161		$	220		$	73		$	102
Service cost		4			7			—			1
Interest cost		8			6			4			3
Benefits paid		(12	)		(15	)		(5	)		(4	)
Actuarial loss (gain)		8			(57	)		(8	)		(29	)
Benefit obligation at end of year	$	169		$	161		$	64		$	73
Fair Value of Plan Assets:
Fair value of plan assets at beginning of year	$	158		$	213		$	—		$	—
Actual return on plan assets		10			(43	)		—			—
Employer contributions		8			3			5			4
Benefits paid		(12	)		(15	)		(5	)		(4	)
Fair value of plan assets at end of year	$	164		$	158		$	—		$	—
Net Funded Status	$	(5	)	$	(3	)	$	(64	)	$	(73	)
Amounts Recognized in Balance Sheet:
Non-current assets	$	1		$	3		$	—		$	—
Current liabilities		—			—			(4	)		(4	)
Non-current liabilities		(6	)		(6	)		(60	)		(69	)
Total liabilities	$	(5	)	$	(3	)	$	(64	)	$	(73	)
Accumulated Other Comprehensive Loss:
Prior service credit	$	1		$	1		$	14		$	24
Actuarial (gain) loss		(7	)		(1	)		33			27
Total	$	(6	)	$	—		$	47		$	51

Projected Benefit Obligation in Excess of Plan Assets and Accumulated Benefit Obligation in Excess of Plan Assets

As of December 31, 2023 and 2022, the projected benefit obligation, the accumulated benefit obligation, and the fair value of plan assets for pension plans with a projected benefit obligation in excess of plan assets and for pension plans with an accumulated benefit obligation in excess of plan assets were as follows (dollars in millions):

	Hourly Plan		Salary Plan
	As of December 31,
	2023	2022	2023		2022
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	N/A 1	N/A 1	$	83	$	79
Fair value of plan assets	N/A 1	N/A 1	$	77	$	73
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	N/A 1	N/A 1	$	79	$	76
Fair value of plan assets	N/A 1	N/A 1	$	77	$	73

(1)As of December 31, 2023 and 2022, the hourly defined pension plan had plan assets greater than the projected benefit obligation and the accumulated benefit obligation.

Net Periodic Benefit Costs

Information about the net periodic benefit cost (credit) and other changes recognized in AOCL for the pension and post-retirement benefit plans is as follows (dollars in millions):

	Pension Plans									Post-retirement Benefits
	Year ended December 31, 2023			Year ended December 31, 2022			Year ended December 31, 2021			Year ended December 31, 2023			Year ended December 31, 2022			Year ended December 31, 2021
Net Periodic Benefit Cost (Credit):
Service cost	$	4		$	7		$	9		$	—		$	1		$	1
Interest cost		8			6			5			4			3			3
Expected return on assets		(8	)		(8	)		(8	)		—			—			—
Prior service credit		—			(1	)		—			(10	)		(10	)		(10	)
Recognized actuarial loss (gain)		—			1			1			(2	)		—			—
Net Periodic Benefit Cost (Credit)	$	4		$	5		$	7		$	(8	)	$	(6	)	$	(6	)
Other changes in other    comprehensive loss (income):
Net loss (gain)	$	6		$	(6	)	$	(6	)	$	(8	)	$	(29	)	$	(5	)
Amortizations		—			—			(1	)		12			10			10
Total recognized – other    comprehensive loss (income)	$	6		$	(6	)	$	(7	)	$	4		$	(19	)	$	5

Weighted-Average Actuarial Assumptions

The table below provides the weighted-average actuarial assumptions used to determine the benefit obligations of the Company’s plans.

	Pension Plans		Post-retirement Benefits
	As of December 31,
	2023	2022	2023	2022
Discount rate	5.00%	5.20%	5.00%	5.20%
Rate of compensation increase (salaried)	3.00%	3.00%	N/A	N/A

The table below provides the weighted-average actuarial assumptions used to determine the net periodic benefit cost (credit).

	Pension Plans			Post-retirement Benefits
	Year ended December 31, 2023	Year ended December 31, 2022	Year ended December 31, 2021	Year ended December 31, 2023	Year ended December 31, 2022	Year ended December 31, 2021
Discount rate	5.20%	2.70%	2.30%	5.20%	2.80%	2.40%
Rate of compensation    increase (salaried)	3.00%	3.00%	3.00%	N/A	N/A	N/A
Expected return on assets	5.30%	3.80%	3.70%	N/A	N/A	N/A

Fair Value of Plan Assets

The fair values of plan assets for the Company’s pension plans as of December 31, 2023 and 2022 are as follows (dollars in millions):

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets (Level 1)				Significant Other Observable Inputs (Level 2)				TOTAL
	2023		2022		2023		2022		2023		2022
Diversified debt securities	$	12	$	8	$	123	$	123	$	135	$	131
Diversified equity securities		18		18		7		7		25		25
Cash equivalents		4		2		—		—		4		2
Total	$	34	$	28	$	130	$	130	$	164	$	158

Schedule of Allocation of Plan Assets

To achieve these objectives the Company has established the following targets:

	Target
Asset Category	Hourly			Salary
Cash equivalents		2	%		2	%
Diversified equity securities		15			15
Diversified debt securities		83			83
Total		100	%		100	%

Expected Cash Flows for Pension and Post-Retirement Benefit Plans

Information about expected cash flows for the Company’s pension and post-retirement benefit plans is as follows (dollars in millions):

	Pension Plans		Post-retirement Benefits
Employer Contributions:
2024 expected contributions	$	—	$	4
Expected Benefit Payments:
2024		11		4
2025		12		5
2026		12		4
2027		12		4
2028		12		4
2029-2033		66		23