v3.20.4
Property, Plant And Equipment (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 327,751 $ 333,538  
Accumulated depreciation and amortization 200,436 203,410  
Property, plant and equipment - net 127,315 130,128 $ 131,473
Land      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost 2,571 2,651  
Buildings and improvements      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 39,418 38,924  
Buildings and improvements | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 2 years    
Buildings and improvements | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 44 years    
Central office equipment      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 95,981 96,061  
Central office equipment | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 3 years    
Central office equipment | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 10 years    
Cable, wiring and conduit      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 75,409 72,042  
Cable, wiring and conduit | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 15 years    
Cable, wiring and conduit | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 50 years    
Satellites      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 908 2,489  
Satellites | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 14 years    
Satellites | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 17 years    
Other equipment      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 90,883 94,951  
Other equipment | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 3 years    
Other equipment | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 20 years    
Software      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 18,482 22,244  
Software | Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 3 years    
Software | Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 7 years    
Under construction      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, at cost $ 4,099 $ 4,176