v3.26.1
Restructuring Costs - Narrative (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2026
Restructuring Cost and Reserve [Line Items]    
Total restructuring plan expenses   $ 175
Network decommissioning    
Restructuring Cost and Reserve [Line Items]    
Total restructuring plan expenses   26
UScellular Acquisition Restructuring Initiatives    
Restructuring Cost and Reserve [Line Items]    
Amortization of the right-of-use assets on lease contracts $ 31 311
Total restructuring plan expenses 90 175
UScellular Acquisition Restructuring Initiatives | Network decommissioning    
Restructuring Cost and Reserve [Line Items]    
Restructuring and related cost, accelerated depreciation 13 242
Total restructuring plan expenses 8 26
Network Optimization Restructuring Initiatives    
Restructuring Cost and Reserve [Line Items]    
Restructuring and related cost, accelerated depreciation 11 71
Total restructuring plan expenses 36 101
Network Optimization Restructuring Initiatives | Network decommissioning    
Restructuring Cost and Reserve [Line Items]    
Amortization of the right-of-use assets on lease contracts 16 27
Total restructuring plan expenses 23 61
Retail Initiatives    
Restructuring Cost and Reserve [Line Items]    
Total restructuring plan expenses $ 108 $ 108