Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Margin Loan) (Details)

v3.10.0.1
Long-Term Debt (Margin Loan) (Details) - Broadband Holdco, LLC - USD ($)
shares in Millions
Oct. 05, 2018
Dec. 29, 2017
Subsequent Event | Revolving Credit Facility    
Debt Instrument [Line Items]    
Line of credit outstanding balance $ 200,000,000  
Subsequent Event | Term Loan Facility    
Debt Instrument [Line Items]    
Line of credit outstanding balance $ 800,000,000  
LIBOR | Subsequent Event    
Debt Instrument [Line Items]    
Variable interest rate 1.85%  
Series C Common Stock    
Debt Instrument [Line Items]    
Number of shares pledged as collateral (in shares)   42.7
Value of shares pledged as collateral   $ 3,600,000,000
Margin Loan Facility    
Debt Instrument [Line Items]    
Line of credit availability   $ 1,000,000,000
Term of debt   2 years
Undrawn commitment fee   1.00%
Margin Loan Facility | Subsequent Event | Revolving Credit Facility    
Debt Instrument [Line Items]    
Line of credit availability $ 200,000,000.0  
Margin Loan Facility | LIBOR    
Debt Instrument [Line Items]    
Variable interest rate   1.85%