Derivative Instruments (Interest Rate Swap Contracts and Options) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Interest Rate Swaption 1 \| Virgin Media
Derivative [Line Items]
Notional amount of derivative	$ 6,352.0
Weighted average remaining life	1 year 6 months
Weighted average strike rate	2.45%
Interest Rate Swaption 2 \| Virgin Media
Derivative [Line Items]
Notional amount of derivative	$ 482.4
Weighted average remaining life	1 year 3 months 18 days
Weighted average strike rate	1.96%
Notional amount due from counterparty \| Interest Rate Swap \| Virgin Media
Derivative [Line Items]
Notional amount of derivative	$ 20,109.9
Weighted average remaining life	3 years 4 months 24 days
Notional amount due from counterparty \| Interest Rate Swap \| UPC Holding
Derivative [Line Items]
Notional amount of derivative	$ 8,340.9
Weighted average remaining life	4 years 2 months 12 days
Notional amount due from counterparty \| Interest Rate Swap \| Telenet
Derivative [Line Items]
Notional amount of derivative	$ 3,775.6
Weighted average remaining life	5 years
Notional amount due to counterparty \| Interest Rate Swap \| Virgin Media
Derivative [Line Items]
Notional amount of derivative	$ 11,225.1
Weighted average remaining life	4 years 10 months 24 days
Notional amount due to counterparty \| Interest Rate Swap \| UPC Holding
Derivative [Line Items]
Notional amount of derivative	$ 5,229.1
Weighted average remaining life	6 years 7 months 6 days
Notional amount due to counterparty \| Interest Rate Swap \| Telenet
Derivative [Line Items]
Notional amount of derivative	$ 1,601.2
Weighted average remaining life	4 years 6 months
Maximum \| Interest Rate Swaption
Derivative [Line Items]
Weighted average remaining life	3 years

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Average fixed interest rate that will be received or paid upon exercise of a group of interest rate swaption contracts.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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