Derivative Instruments (Interest Rate Swap Contracts, Options and Basis Swaps) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2026 USD ($)
Interest Rate Swap \| Notional amount due from counterparty \| VodafoneZiggo
Derivative [Line Items]
Notional amount	$ 4,962.6
Weighted average remaining life	3 years 3 months 18 days
Interest Rate Swap \| Notional amount due from counterparty \| Telenet
Derivative [Line Items]
Notional amount	$ 4,093.6
Weighted average remaining life	2 years 7 months 6 days
Interest Rate Swap \| Notional amount due from counterparty \| Wyre
Derivative [Line Items]
Notional amount	$ 2,990.3
Weighted average remaining life	6 years 9 months 18 days
Interest Rate Swap \| Notional amount due from counterparty \| Other
Derivative [Line Items]
Notional amount	$ 288.1
Weighted average remaining life	17 years 6 months
Interest Rate Swap \| Notional amount due to counterparty \| VodafoneZiggo
Derivative [Line Items]
Notional amount	$ 1,780.1
Weighted average remaining life	1 year 4 months 24 days
Interest Rate Swap \| Notional amount due to counterparty \| Telenet
Derivative [Line Items]
Notional amount	$ 800.0
Weighted average remaining life	1 year 7 months 6 days
Interest Rate Swap \| Notional amount due to counterparty \| Wyre
Derivative [Line Items]
Notional amount	$ 0.0
Interest Rate Swap \| Notional amount due to counterparty \| Other
Derivative [Line Items]
Notional amount	0.0
Basis Swaps \| VodafoneZiggo
Derivative [Line Items]
Notional amount	$ 2,551.4
Weighted average remaining life	7 months 6 days
Basis Swaps \| Wyre
Derivative [Line Items]
Notional amount	$ 2,983.4
Weighted average remaining life	9 months 18 days
Basis Swaps \| VM Ireland
Derivative [Line Items]
Notional amount	$ 1,020.6
Weighted average remaining life	3 months 18 days