v3.20.4
Tower Obligations - Narrative (Details)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2020
USD ($)
tower_site
Dec. 31, 2020
USD ($)
tower_site
Dec. 31, 2012
USD ($)
tower_site
Apr. 01, 2020
USD ($)
Sale Leaseback Transaction [Line Items]        
Lease liabilities   $ 30,587    
Sprint        
Sale Leaseback Transaction [Line Items]        
Property and equipment       $ 18,435
Adjustment, other long-term liabilities   $ 1,700    
Crown Castle International Corp.        
Sale Leaseback Transaction [Line Items]        
Managed sites | tower_site   900    
Lease liabilities   $ 282    
Minimum        
Sale Leaseback Transaction [Line Items]        
Lessee leasing arrangements, operating leases, term of contract (years)   5 years    
Maximum        
Sale Leaseback Transaction [Line Items]        
Lessee leasing arrangements, operating leases, term of contract (years)   15 years    
Tower Transaction        
Sale Leaseback Transaction [Line Items]        
Number of wireless communications tower sites sold | tower_site     7,100  
Lessee leasing arrangements, operating leases, term of contract (years)     10 years  
Sale leaseback transaction, fixed-price purchase options     $ 2,000  
Interest rate on tower obligations   6.00% 8.00%  
Tower Transaction | Tower        
Sale Leaseback Transaction [Line Items]        
Useful life (in years)   20 years    
Tower Transaction | Crown Castle International Corp.        
Sale Leaseback Transaction [Line Items]        
Property subject to failed sale leaseback transaction, number of units | tower_site 6,400      
Remaining term of lease 17 years      
Fixed-price purchase option on leased or subleased sites $ 2,300      
Fixed-price purchase option on lease or subleased sites, exercisable period 1 year      
Days prior to expiration of agreement 120 days      
Initial term 10 years      
Property and equipment       2,800
Tower obligations       $ 1,100
Tower Transaction | Minimum        
Sale Leaseback Transaction [Line Items]        
Lessee leasing arrangements, operating leases, term of contract (years)     23 years  
Tower Transaction | Maximum        
Sale Leaseback Transaction [Line Items]        
Lessee leasing arrangements, operating leases, term of contract (years)     37 years