v3.19.3.a.u2
Tower Transaction (Narrative) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Other Liabilities [Line Items]      
Property, Plant and Equipment - Net $ 130,128 $ 131,473 $ 125,222
Depreciation expense $ 20,285 20,083 19,761
Crown Castle International [Member]      
Other Liabilities [Line Items]      
Number Of Towers Subject To Failed Sale-Leaseback 9,048    
Number of towers subject to disposition (as shown) 627    
Cash from failed sale-leaseback (in millions U.S. dollars) $ 4,827    
Term of lease 28 years    
Approximate fixed future purchase option price on failed sale-leaseback (in millions U.S. dollars) $ 4,200    
Minimum Leaseback Term 10 years    
Property, Plant and Equipment - Net $ 804 843  
Depreciation expense $ 39 $ 39 $ 39
Approximate annual interest rate - financing obligation (as shown) 3.90%    
Lease payments $ 244    
Minimum lease payments - 2020 248    
Minimum lease payments - 2021 253    
Minimum lease payments - 2022 258    
Minimum lease payments - 2023 264    
Minimum lease payments - 2024 269    
Minimum lease payments - thereafter $ 1,427