Debt (Narrative) (Details)	1 Months Ended						9 Months Ended
	Oct. 31, 2023 EUR (€)	Oct. 31, 2023 USD ($)	Sep. 30, 2023 EUR (€) group	Sep. 30, 2023 USD ($)	Jul. 31, 2023 EUR (€)	Jul. 31, 2023 USD ($)	Sep. 30, 2023 EUR (€) subsidiary group	Oct. 31, 2023 USD ($)	Sep. 30, 2023 USD ($) group	Jun. 08, 2023 EUR (€)	Jun. 08, 2023 USD ($)
Debt Instrument [Line Items]
Number of subsidiaries with the most outstanding debt | subsidiary							1
Number of borrowing groups | group			3				3		3
UPC Revolving Facility One
Debt Instrument [Line Items]
Maximum borrowing capacity			€ 736,400,000				€ 736,400,000		$ 778,900,000
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V.
Debt Instrument [Line Items]
Maximum borrowing capacity										€ 1,000,000,000	$ 1,100,000,000
Proceeds from lines of credit			€ 67,500,000	$ 71,400,000	€ 745,000,000	$ 788,000,000
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V. | Subsequent Event
Debt Instrument [Line Items]
Proceeds from lines of credit	€ 77,500,000	$ 82,000,000
Available borrowings	€ 110,000,000							$ 116,400,000
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V. | EURIBOR
Debt Instrument [Line Items]
Floor rate										0.00%	0.00%
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V. | First year from the Closing Date | EURIBOR
Debt Instrument [Line Items]
Basis spread on variable rate							4.00%
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V. | Second year from the Closing Date | EURIBOR
Debt Instrument [Line Items]
Basis spread on variable rate							4.50%
Secured Debt | LGBH Facility B | Line of Credit | Subsidiaries | Liberty Global Belgium Holding B.V. | Third year from the Closing Date | EURIBOR
Debt Instrument [Line Items]
Basis spread on variable rate							5.25%