Derivative Instruments (Cross-currency Derivative Contracts) (Details) - 3 months ended Mar. 31, 2020 € in Millions, £ in Millions, zł in Millions, SFr in Millions, $ in Millions	GBP (£)	CHF (SFr)	PLN (zł)	EUR (€)	USD ($)
Virgin Media
Derivative [Line Items]
Derivative instruments that do not involve the exchange of notional amounts at the inception and maturity					$ 2,900.0
Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Weighted average remaining life	5 years 4 months 24 days
Virgin Media | Cross-Currency Swap 2
Derivative [Line Items]
Weighted average remaining life	4 years 9 months 18 days
Virgin Media | Cross-Currency Swap 3
Derivative [Line Items]
Weighted average remaining life	2 years 9 months 18 days
UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Weighted average remaining life	5 years 6 months
UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Weighted average remaining life	6 years 2 months 12 days
UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Weighted average remaining life	4 years 4 months 24 days
UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Weighted average remaining life	1 year 9 months 18 days
Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Weighted average remaining life	6 years 9 months 18 days
Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Weighted average remaining life	4 years 9 months 18 days
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Notional amount of derivative					10,857.5
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 2
Derivative [Line Items]
Notional amount of derivative | £	£ 2,296.2
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 3
Derivative [Line Items]
Notional amount of derivative | €				€ 246.3
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Notional amount of derivative					360.0
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Notional amount of derivative					1,600.0
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Notional amount of derivative | €				2,618.3
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Notional amount of derivative | €				707.0
Notional amount due from counterparty | Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Notional amount of derivative					3,940.0
Notional amount due from counterparty | Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Notional amount of derivative | €				45.2
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Notional amount of derivative | £	£ 8,003.6
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 2
Derivative [Line Items]
Notional amount of derivative					3,300.0
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 3
Derivative [Line Items]
Notional amount of derivative					271.1
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Notional amount of derivative | €				267.9
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Notional amount of derivative | SFr		SFr 1,476.1
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Notional amount of derivative | SFr		SFr 2,941.4
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Notional amount of derivative | zł			zł 2,999.5
Notional amount due to counterparty | Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Notional amount of derivative | €				€ 3,489.6
Notional amount due to counterparty | Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Notional amount of derivative					$ 50.0