Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Fair Value of Debt (Details)

v3.19.3
Long-Term Debt - Fair Value of Debt (Details) - USD ($)
$ in Millions
Sep. 30, 2019
Feb. 01, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Long-term debt, measured at fair value $ 2,812   $ 2,487
Liberty Sirius XM Group | Sirius XM 3.875% Senior Notes due 2022      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 3.875%    
Long-term debt, measured at fair value $ 1,016    
Liberty Sirius XM Group | Sirius XM 4.625% Senior Notes Due 2023      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 4.625%    
Long-term debt, measured at fair value $ 509    
Liberty Sirius XM Group | Sirius Xm 4.625% Senior Notes Due 2024      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 4.625%    
Long-term debt, measured at fair value $ 1,558    
Liberty Sirius XM Group | Sirius XM 5.375% Senior Notes Due 2025      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 5.375%    
Long-term debt, measured at fair value $ 1,038    
Liberty Sirius XM Group | Sirius XM 5.375% Senior Notes due 2026      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 5.375%    
Long-term debt, measured at fair value $ 1,048    
Liberty Sirius XM Group | Sirius XM 5.0% Senior Notes due 2027      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 5.00%    
Long-term debt, measured at fair value $ 1,553    
Liberty Sirius XM Group | Sirius Xm 5.50% Senior Notes Due 2029      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 5.50%    
Long-term debt, measured at fair value $ 1,333    
Liberty Sirius XM Group | Pandora 1.75% Convertible Senior Notes due 2020      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 1.75% 1.75%  
Long-term debt, measured at fair value $ 1    
Liberty Sirius XM Group | Pandora 1.75% Convertible Senior Notes due 2023      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Debt instrument interest rate (as a percent) 1.75% 1.75%  
Long-term debt, measured at fair value $ 226