Derivative Instruments (Cross-currency Derivative Contracts) (Details) - 9 months ended Sep. 30, 2019 € in Millions, £ in Millions, zł in Millions, SFr in Millions, Ft in Millions, $ in Millions	CHF (SFr)	EUR (€)	USD ($)	HUF (Ft)	PLN (zł)	GBP (£)
Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Weighted average remaining life	3 years 3 months 18 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	5 years 3 months 18 days
UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Weighted average remaining life	4 years 9 months 18 days
UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Weighted average remaining life	5 years 6 months
UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Weighted average remaining life	4 years 7 months 6 days
UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Weighted average remaining life	2 years 2 months 12 days
UPC Holding | Cross-Currency Swap 8
Derivative [Line Items]
Weighted average remaining life	2 years 3 months 18 days
UPC Holding | Cross-Currency Swap 9
Derivative [Line Items]
Weighted average remaining life	2 years 3 months 18 days
Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Weighted average remaining life	5 years 9 months 18 days
Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Weighted average remaining life	5 years 8 months 12 days
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Notional amount of derivative | $			$ 400.0
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 2
Derivative [Line Items]
Notional amount of derivative | $			8,036.4
Notional amount due from counterparty | Virgin Media | Cross-Currency Swap 3
Derivative [Line Items]
Notional amount of derivative | £						£ 2,365.8
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Notional amount of derivative | $			2,420.0
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Notional amount of derivative | $			1,200.0
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Notional amount of derivative		€ 2,824.4
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Notional amount of derivative		742.8
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 8
Derivative [Line Items]
Notional amount of derivative		78.0
Notional amount due from counterparty | UPC Holding | Cross-Currency Swap 9
Derivative [Line Items]
Notional amount of derivative | Ft				Ft 19,500.0
Notional amount due from counterparty | Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Notional amount of derivative | $			3,670.0
Notional amount due from counterparty | Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Notional amount of derivative		1,431.2
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 1
Derivative [Line Items]
Notional amount of derivative		339.6
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 2
Derivative [Line Items]
Notional amount of derivative | £						£ 5,451.8
Notional amount due to counterparty | Virgin Media | Cross-Currency Swap 3
Derivative [Line Items]
Notional amount of derivative | $			3,400.0
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 4
Derivative [Line Items]
Notional amount of derivative		1,999.4
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 5
Derivative [Line Items]
Notional amount of derivative | SFr	SFr 1,107.5
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 6
Derivative [Line Items]
Notional amount of derivative | SFr	SFr 3,221.2
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 7
Derivative [Line Items]
Notional amount of derivative | zł					zł 3,149.5
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 8
Derivative [Line Items]
Notional amount of derivative | Ft				Ft 19,500.0
Notional amount due to counterparty | UPC Holding | Cross-Currency Swap 9
Derivative [Line Items]
Notional amount of derivative		61.0
Notional amount due to counterparty | Telenet | Cross-Currency Swap 10
Derivative [Line Items]
Notional amount of derivative		€ 3,243.6
Notional amount due to counterparty | Telenet | Cross-Currency Swap 11
Derivative [Line Items]
Notional amount of derivative | $			$ 1,600.0