v3.20.2
Debt - Debt Assumed (Details) - USD ($)
Jun. 30, 2020
Jun. 24, 2020
Apr. 09, 2020
Apr. 01, 2020
Debt Instrument [Line Items]        
Principal Outstanding $ 46,000,000,000      
Sprint        
Debt Instrument [Line Items]        
Fair value       $ 31,797,000,000
Principal Outstanding 26,649,000,000      
Carrying Value 29,035,000,000      
Accounts receivable facility | Sprint        
Debt Instrument [Line Items]        
Fair value       2,310,000,000
Principal Outstanding 0      
Carrying Value 0      
Other debt | Sprint        
Debt Instrument [Line Items]        
Fair value       $ 464,000,000
Principal Outstanding 362,000,000      
Carrying Value 353,000,000      
Senior Notes        
Debt Instrument [Line Items]        
Principal Outstanding   $ 4,000,000,000.0 $ 19,000,000,000.0  
Senior Notes | Senior Notes due 2021, 7.250% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       725.00%
Fair value       $ 2,324,000,000
Principal Outstanding 2,250,000,000      
Carrying Value 2,312,000,000      
Senior Notes | Senior Notes due 2023, 7.875% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       787.50%
Fair value       $ 4,682,000,000
Principal Outstanding 4,250,000,000      
Carrying Value 4,653,000,000      
Senior Notes | Senior Notes due 2024, 7.125% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       712.50%
Fair value       $ 2,746,000,000
Principal Outstanding 2,500,000,000      
Carrying Value 2,733,000,000      
Senior Notes | Senior Notes due 2025, 7.625% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       762.50%
Fair value       $ 1,677,000,000
Principal Outstanding 1,500,000,000      
Carrying Value 1,669,000,000      
Senior Notes | Senior Notes due 2026, 7.625% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       762.50%
Fair value       $ 1,701,000,000
Principal Outstanding 1,500,000,000      
Carrying Value $ 1,694,000,000      
Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%        
Debt Instrument [Line Items]        
Interest rate, stated percentage 3.36%      
Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       336.00%
Fair value       $ 1,310,000,000
Principal Outstanding $ 1,094,000,000     $ 3,500,000,000
Carrying Value 1,092,000,000      
Senior Notes | Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       473.80%
Fair value       $ 2,153,000,000
Principal Outstanding       $ 2,100,000,000
Carrying Value 2,150,000,000      
Senior Notes | Senior Secured Series 2018-1 A-2 Notes due 2028, 5.152% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       515.20%
Fair value       $ 1,960,000,000
Principal Outstanding       $ 1,838,000,000
Carrying Value 1,957,000,000      
Senior Notes | Senior Notes due 2020, 7.000% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       700.00%
Fair value       $ 1,510,000,000
Principal Outstanding 1,500,000,000      
Carrying Value 1,503,000,000      
Senior Notes | Senior Notes due 2021, 11.500% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       1150.00%
Fair value       $ 1,105,000,000
Principal Outstanding 1,000,000,000      
Carrying Value 1,090,000,000      
Senior Notes | Senior Notes due 2022, 6.000% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       600.00%
Fair value       $ 2,372,000,000
Principal Outstanding 2,280,000,000      
Carrying Value 2,363,000,000      
Senior Notes | Senior Notes due 2028, 6.875% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       687.50%
Fair value       $ 2,834,000,000
Principal Outstanding 2,475,000,000      
Carrying Value 2,826,000,000      
Senior Notes | Senior Notes due 2032, 8.750% | Sprint        
Debt Instrument [Line Items]        
Interest rate, stated percentage       875.00%
Fair value       $ 2,649,000,000
Principal Outstanding 2,000,000,000      
Carrying Value $ 2,640,000,000