v3.25.4
Commitments and Contingencies (Tables)
12 Months Ended
Dec. 31, 2025
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)202520242023
Severance$2 $6 $9 
Facility abandonment— 2 2 
Total
$2 $8 $11 
The following is a summary of changes in the restructuring provision balance during the years ended December 31, 2025 and 2024:
(Dollars in millions)
Balance at January 1, 2024$10 
Additional provision8 
Reversal and utilization(17)
Balance at December 31, 20241 
Additional provision2 
Reversal and utilization(2)
Balance at December 31, 2025$1 
Schedule of Product Warranty Liability The following is a summary of changes in the product warranty balances during the years ended December 31, 2025 and 2024:
(Dollars in millions)
Balance at January 1, 2024$26 
Additional provision16 
Reversal and utilization(13)
Balance at December 31, 2024$29 
Additional provision25 
Reversal and utilization(21)
Balance at December 31, 2025$33