Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

Schedule of Restructuring Costs incurred by Segment and by Nature of Cost incurred and Restructuring Provision

See the table below for a breakout of restructuring costs by nature of cost incurred:

	Year Ended December 31,
(Dollars in millions)	2024		2023		2022
Severance	$	6	$	9	$	2
Facility abandonment	2		2		1
Total	$	8	$	11	$	3

The following is a summary of changes in the restructuring provision balance during the years ended December 31, 2024 and 2023:

(Dollars in millions)
Balance at January 1, 2023	$	4
Additional provision	11
Reversal and utilization	(5)
Balance at December 31, 2023	10
Additional provision	8
Reversal and utilization	(17)
Balance at December 31, 2024	$	1

Schedule of Product Warranty Liability

The following is a summary of changes in the product warranty balances during the years ended December 31, 2023 and 2024:

(Dollars in millions)
Balance at January 1, 2023	$	18
Additional provision	20
Reversal and utilization	(12)
Balance at December 31, 2023	$	26
Additional provision	16
Reversal and utilization	(13)
Balance at December 31, 2024	$	29