Fair Value Measurements (Narrative) (Details) - Discount rate - VodafoneZiggo Acquisition - Fair value, nonrecurring - Significant unobservable inputs (Level 3)	Sep. 30, 2026
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest acquired	5.75%
VodafoneZiggo
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest acquired	5.75%
Telenet
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest acquired	6.50%
Ziggo Group
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity interest issued as consideration percentage	10.00%

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.

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