text: Nine Months Ended 
  September 30,  Change  Change 
  
  $  %  2024  2023  $  % 
  
  (Dollars in millions) 
  Interest income  52 % $  1,127 $  733 $  394  54 % 
  
  Interest income increased $147 million, or 52%, in the three months ended September 30, 2024 and increased $394 
  million, or 54%, in the nine months ended September 30, 2024 as compared to the three and nine months ended September 30, 
  2023, respectively. The increases were primarily due to higher interest earned on our cash and cash equivalents and short-term 
  investments compared to the prior periods due to increases in our portfolio balance and higher interest rates. 
  
  Other (Expense) Income, Net 
  
  Three Months Ended 
  September 30,  Nine Months Ended 
  September 30,  Change  Change 
  
  2024  2023  $  %  2024  2023  $  %  (Dollars in millions) 
  
  Not 
  Not 
  meaningful  $  (270) $  37 $  (307)  meaningful $  (142) $  317 $  (459)  Other (expense) income, net 
  
  Other (expense) income, net, changed unfavorably by $307 million in the three months ended September 30, 2024 as 
  
  compared to the three months ended September 30, 2023. Other (expense) income, net changed unfavorably by $459 million in 
  the nine months ended September 30, 2024 as compared to the nine months ended September 30, 2023. The unfavorable 
  changes were primarily due to fluctuations in foreign currency exchange rates on our intercompany balances. As our 
  intercompany balances are significant in nature and we do not typically hedge foreign currency risk, we can experience 
  significant fluctuations in foreign currency exchange rate gains and losses from period to period. 