v3.26.3
Long-Term Debt and Credit Facilities - Exchange Offers and Consent Solicitations (Details)
$ in Millions
 9 Months Ended
Sep. 30, 2026
USD ($)
Jun. 11, 2026
USD ($)
debt_instrument
Long-term Debt and Credit Facilities    
Debt modification expense $ 10  
Qwest Corporation | Senior Notes    
Long-term Debt and Credit Facilities    
Number of debt instruments issued | debt_instrument   2
Qwest Corporation | Senior Notes | 6.500% Notes due 2051    
Long-term Debt and Credit Facilities    
Stated interest rate (as a percent)   6.50%
Debt instrument, face amount   $ 1,002
Qwest Corporation | Senior Notes | 6.750% Notes due 2052    
Long-term Debt and Credit Facilities    
Stated interest rate (as a percent)   6.75%
Debt instrument, face amount   $ 382
Qwest Corporation | Senior Notes | 6.500% Notes due 2056    
Long-term Debt and Credit Facilities    
Stated interest rate (as a percent) 6.50% 6.50%
Debt instrument, face amount   $ 146
Qwest Corporation | Senior Notes | 6.750% Notes due 2057    
Long-term Debt and Credit Facilities    
Stated interest rate (as a percent) 6.75% 6.75%
Debt instrument, face amount   $ 108