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