Derivative Instruments (Impact of Derivative Instruments on Borrowing Costs) (Details)
Dec. 31, 2019
Derivative [Line Items]  
Increase (decrease) to borrowing costs (0.27%)
Virgin Media  
Derivative [Line Items]  
Increase (decrease) to borrowing costs (0.20%)
UPC Holding  
Derivative [Line Items]  
Increase (decrease) to borrowing costs (0.15%)
Telenet  
Derivative [Line Items]  
Increase (decrease) to borrowing costs (0.58%)