Derivative Instruments (Cross-currency Derivative Contracts) (Details) - 12 months ended Dec. 31, 2019
€ in Millions, £ in Millions, zł in Millions, SFr in Millions, $ in Millions
USD ($)
EUR (€)
CHF (SFr)
GBP (£)
PLN (zł)
Virgin Media | Cross-Currency Swap 1          
Derivative [Line Items]          
Weighted average remaining life 5 years 7 months 6 days        
Virgin Media | Cross-Currency Swap 2          
Derivative [Line Items]          
Weighted average remaining life 5 years 1 month 6 days        
Virgin Media | Cross-Currency Swap 3          
Derivative [Line Items]          
Weighted average remaining life 3 years        
UPC Holding | Cross-Currency Swap 4          
Derivative [Line Items]          
Weighted average remaining life 4 years 3 months 18 days        
UPC Holding | Cross-Currency Swap 5          
Derivative [Line Items]          
Weighted average remaining life 5 years 2 months 12 days        
UPC Holding | Cross-Currency Swap 6          
Derivative [Line Items]          
Weighted average remaining life 4 years 3 months 18 days        
UPC Holding | Cross-Currency Swap 9          
Derivative [Line Items]          
Weighted average remaining life 1 year 10 months 24 days        
Telenet | Cross-Currency Swap 11          
Derivative [Line Items]          
Weighted average remaining life 6 years        
Telenet | Cross-Currency Swap 12          
Derivative [Line Items]          
Weighted average remaining life 6 years        
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 1          
Derivative [Line Items]          
Notional amount $ 10,857.5        
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 2          
Derivative [Line Items]          
Notional amount | £       £ 2,296.2  
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 3          
Derivative [Line Items]          
Notional amount | €   € 246.3      
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 4          
Derivative [Line Items]          
Notional amount 775.0        
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 5          
Derivative [Line Items]          
Notional amount 1,200.0        
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 6          
Derivative [Line Items]          
Notional amount | €   2,824.4      
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 9          
Derivative [Line Items]          
Notional amount | €   742.8      
Notional amount due from counterparty | Telenet | Cross-Currency Swap 11          
Derivative [Line Items]          
Notional amount 3,940.0        
Notional amount due from counterparty | Telenet | Cross-Currency Swap 12          
Derivative [Line Items]          
Notional amount | €   291.5      
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 1          
Derivative [Line Items]          
Notional amount | £       £ 8,003.6  
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 2          
Derivative [Line Items]          
Notional amount 3,300.0        
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 3          
Derivative [Line Items]          
Notional amount 271.1        
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 4          
Derivative [Line Items]          
Notional amount | €   643.1      
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 5          
Derivative [Line Items]          
Notional amount | SFr     SFr 1,107.5    
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 6          
Derivative [Line Items]          
Notional amount | SFr     SFr 3,221.2    
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 9          
Derivative [Line Items]          
Notional amount | zł         zł 3,149.5
Notional amount due to counterparty | Telenet | Cross-Currency Swap 11          
Derivative [Line Items]          
Notional amount | €   € 3,489.6      
Notional amount due to counterparty | Telenet | Cross-Currency Swap 12          
Derivative [Line Items]          
Notional amount $ 350.0