v3.22.0.1
Discontinued Operations - Components of Discontinued Operations from Merger Date (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Income from discontinued operations $ 0 $ 320 $ 0
Discontinued Operations, Disposed of by Sale | Prepaid Transaction      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Service revenues   1,270  
Selling, general and administrative   314  
Total operating expenses   838  
Pretax income from discontinued operations   432  
Income tax expense   (112)  
Income from discontinued operations   320  
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Prepaid revenues      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Service revenues   973  
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Roaming and other services revenue      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Service revenues   27  
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Service      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Service revenues   1,000  
Cost of services and sales   25  
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Equipment revenues      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Service revenues   270  
Cost of services and sales   $ 499