v3.25.3
Intangible Assets
 9 Months Ended
Sep. 30, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Intangible Assets Intangible Assets
Intangible assets consists of the following:
September 30, 2025December 31, 2024
(Dollars in millions)Gross Carrying AmountAccumulated AmortizationNet Carrying AmountGross Carrying AmountAccumulated AmortizationNet Carrying Amount
Acquired intangible assets$1,087 $(978)$109 $1,087 $(962)$125 
Patents and licenses14 (9)5 14 (7)7 
Total intangible assets
$1,101 $(987)$114 $1,101 $(969)$132 
Amortization expense related to acquired intangible assets was $5 million and $16 million for the three and nine months ended September 30, 2025, respectively, and $6 million and $17 million for the three and nine months ended September 30, 2024, respectively.