v3.26.3
Revenue Recognition - Revenue from contracts with customers (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Revenue Recognition        
Revenue $ 267 $ 257 $ 784 $ 784
Consumer Revenue, Data        
Revenue Recognition        
Revenue 60 59 179 180
Consumer Revenue, Wireless        
Revenue Recognition        
Revenue 37 35 109 104
Consumer Revenue, Other        
Revenue Recognition        
Revenue 5 4 13 22
Business Revenue, Data        
Revenue Recognition        
Revenue 131 124 381 375
Business Revenue, Wireless        
Revenue Recognition        
Revenue 8 8 24 24
Business Revenue, Other        
Revenue Recognition        
Revenue 2 3 7 8
Lease, grant, and revenue from subsidies        
Revenue Recognition        
Revenue $ 24 $ 24 $ 71 $ 71