Debt (Components of Debt) (Details) € in Millions, $ in Millions	Mar. 31, 2025 EUR (€)	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Weighted average interest rate	5.08%	5.08%
Unused borrowing capacity, amount		$ 773.0
Total debt before deferred financing costs, discounts and premiums		9,404.4	$ 9,145.0
Deferred financing costs, discounts and premiums, net		(65.2)	(78.1)
Total carrying amount of debt		9,339.2	9,066.9
Finance lease obligations		34.1	34.1
Total debt and finance lease obligations		9,373.3	9,101.0
Current portion of debt and finance lease obligations		(1,127.7)	(898.5)
Long-term debt and finance lease obligations		$ 8,245.6	8,202.5
Telenet Credit Facility
Debt Instrument [Line Items]
Weighted average interest rate	5.71%	5.71%
Total debt before deferred financing costs, discounts and premiums		$ 4,457.3	4,364.8
Telenet Credit Facility | Sunrise Holding Revolving Facility
Debt Instrument [Line Items]
Unused borrowing capacity, amount	€ 615.0	$ 664.9
Telenet Senior Secured Notes
Debt Instrument [Line Items]
Weighted average interest rate	4.76%	4.76%
Total debt before deferred financing costs, discounts and premiums		$ 1,583.8	1,558.8
VM Ireland Credit Facility
Debt Instrument [Line Items]
Weighted average interest rate	5.93%	5.93%
Unused borrowing capacity, amount	€ 100.0	$ 108.1
Total debt before deferred financing costs, discounts and premiums		973.0	931.4
VM Ireland Credit Facility | Sunrise Holding Revolving Facility
Debt Instrument [Line Items]
Unused borrowing capacity, amount	€ 100.0	$ 108.1
Vodafone Collar Loan
Debt Instrument [Line Items]
Weighted average interest rate	2.95%	2.95%
Total debt before deferred financing costs, discounts and premiums		$ 1,360.1	1,301.9
Vendor financing
Debt Instrument [Line Items]
Weighted average interest rate	5.00%	5.00%
Total debt before deferred financing costs, discounts and premiums		$ 370.5	355.9	$ 389.0	$ 399.1
Other
Debt Instrument [Line Items]
Weighted average interest rate	4.82%	4.82%
Total debt before deferred financing costs, discounts and premiums		$ 659.7	$ 632.2