Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2023

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)	2023		2022		2021
Severance	$	9	$	2	$	5
Facility abandonment	2		1		—
Total	$	11	$	3	$	5

The following is a summary of changes in the restructuring provision balance during the years ended December 31, 2023 and 2022:

(Dollars in millions)
Balance at January 1, 2022	$	4
Additional provision	3
Reversal and utilization	(3)
Balance at December 31, 2022	4
Additional provision	11
Reversal and utilization	(5)
Balance at December 31, 2023	$	10

Schedule of Product Warranty Liability

The following is a summary of changes in the product warranty balances during the years ended December 31, 2022 and 2023:

(Dollars in millions)
Balance at January 1, 2022	$	19
Additional provision	10
Reversal and utilization	(11)
Balance at December 31, 2022	$	18
Additional provision	20
Reversal and utilization	(12)
Balance at December 31, 2023	$	26