v3.26.1
Employee Benefits - Additional Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mass Markets Fiber-to-the Home Business        
Employee Benefits        
Recognition of prior service costs (credits)     $ (6)  
Combined Pension Plan        
Employee Benefits        
Settlement charges $ 0 $ 0 9 $ 0
Curtailment gain (loss) 0 0 5 0
Recognition of prior service costs (credits) 0 (1) 0 (1)
Service cost 5 6 9 11
Contributions 101      
Combined Pension Plan | Mass Markets Fiber-to-the Home Business        
Employee Benefits        
Curtailment gain (loss)     5  
Post-Retirement Benefit Plan        
Employee Benefits        
Curtailment gain (loss) 0 0 (10) 0
Recognition of prior service costs (credits) (1) (1) (2) (3)
Service cost $ 0 $ 1 1 $ 2
Post-Retirement Benefit Plan | Mass Markets Fiber-to-the Home Business        
Employee Benefits        
Curtailment gain (loss)     (10)  
Recognition of prior service costs (credits)     $ 1