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Long-Term Debt and Revolving Promissory Note - Additional Information (Details) - USD ($)
Jun. 30, 2018
Dec. 31, 2017
Sep. 30, 2017
Apr. 18, 2012
Long-term debt        
Note payable - affiliate $ 981,000,000 $ 965,000,000    
Interest 77,000,000 77,000,000    
Qwest Corporation | Affiliated entity | Loans payable        
Long-term debt        
Debt instrument, face amount     $ 965,000,000 $ 1,000,000,000
Note payable - affiliate $ 981,000,000 $ 965,000,000    
Weighted average interest rate 5.466%      
Interest $ 27,000,000