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Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Narrative (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
asset_group
unit
reporting_unit
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Basis of presentation      
Number of wireless connections 5,000,000    
Wireline and Cable connections 1,200,000    
FCC licenses, number of accounting units | unit 8    
FCC licenses, number of accounting units, built licenses | unit 1    
FCC licenses, number of accounting units, unbuilt licenses | unit 7    
Advertising costs $ 213,000,000 $ 227,000,000 $ 230,000,000
Amortization of implementation costs 11,000,000    
UScellular      
Basis of presentation      
Agent liability $ 55,000,000 59,000,000  
TDS Telecom      
Basis of presentation      
Number of reporting units | reporting_unit 2    
Asset groups | asset_group 2    
Wireline      
Basis of presentation      
Loss on impairment of goodwill $ 0 0  
Cable      
Basis of presentation      
Loss on impairment of goodwill $ 0 0  
UScellular      
Basis of presentation      
Asset groups | asset_group 1    
TDS Telecom | Franchise rights      
Basis of presentation      
Renewal period 10 years    
Licenses      
Basis of presentation      
Renewal period 12 years    
Licenses | UScellular      
Basis of presentation      
Impairment of intangible assets $ 0 $ 0  
Minimum      
Basis of presentation      
Amortization period 3 years    
Minimum | Leasehold Improvements      
Basis of presentation      
Useful life 1 year    
Minimum | Licenses      
Basis of presentation      
Renewal period 10 years    
Maximum      
Basis of presentation      
Amortization period 5 years    
Maximum | Leasehold Improvements      
Basis of presentation      
Useful life 30 years    
Maximum | Licenses      
Basis of presentation      
Renewal period 15 years    
UScellular      
Basis of presentation      
TDS ownership of UScellular 82.00%