v3.20.2
Goodwill, Spectrum License Transactions and Other Intangible Assets - Spectrum Licenses (Details)
$ in Millions
1 Months Ended 3 Months Ended 6 Months Ended
Apr. 08, 2020
USD ($)
Apr. 30, 2020
USD ($)
Mar. 31, 2020
USD ($)
license
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Oct. 31, 2019
USD ($)
Indefinite-lived Intangible Assets [Roll Forward]                
Purchase of spectrum licenses       $ 745.0 $ 665.0 $ 844.0 $ 850.0  
Licensing Agreements                
Indefinite-lived Intangible Assets [Roll Forward]                
Beginning balance           36,465.0    
Spectrum license acquisitions           987.0    
Costs to clear spectrum           18.0    
Ending balance       $ 82,870.0   82,870.0    
Licensing Agreements | Auction 103                
Indefinite-lived Intangible Assets [Roll Forward]                
Number of licenses | license     2,384          
Purchase of spectrum licenses $ 698.0   $ 873.0          
Asset purchase deposit               $ 82.0
Incentive payments     59.0          
Down payment     $ 93.0          
Licensing Agreements | Auction 103 | Sprint                
Indefinite-lived Intangible Assets [Roll Forward]                
Number of licenses | license     127          
Sprint | Licensing Agreements                
Indefinite-lived Intangible Assets [Roll Forward]                
Spectrum license acquisitions           $ 45,400.0    
Sprint | Licensing Agreements | 800 MHz, 1.9 GHz and 2.5 GHz                
Indefinite-lived Intangible Assets [Roll Forward]                
Purchase of spectrum licenses   $ 45,400.0