v3.25.2
Investments (Debt Securities) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis $ 0.0 $ 344.6
Accumulated unrealized gains (losses) 0.0 0.5
Fair value 82.8 433.1
Commercial paper    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis 0.0 72.0
Accumulated unrealized gains (losses) 0.0 (0.1)
Fair value 0.0 71.9
Government bonds    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis 0.0 129.4
Accumulated unrealized gains (losses) 0.0 0.4
Fair value 0.0 129.8
Certificates of deposit    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis 0.0 70.5
Accumulated unrealized gains (losses) 0.0 0.0
Fair value 0.0 70.5
Corporate debt securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis 0.0 66.4
Accumulated unrealized gains (losses) 0.0 0.2
Fair value 0.0 66.6
Structured notes    
Debt Securities, Available-for-sale [Line Items]    
Fair value $ 82.8 $ 88.0
Debt instrument, proportion of debt associated with return 100.00% 100.00%
Structured notes | Affiliate | VodafoneZiggo JV    
Debt Securities, Available-for-sale [Line Items]    
Debt instrument, proportion of debt associated with return 33.50% 33.90%
Structured notes | Affiliate | VMO2 JV    
Debt Securities, Available-for-sale [Line Items]    
Debt instrument, proportion of debt associated with return 30.20% 0.00%
Structured notes | Affiliate | Other    
Debt Securities, Available-for-sale [Line Items]    
Debt instrument, proportion of debt associated with return 0.00% 34.00%
Structured notes | Telenet | Subsidiaries    
Debt Securities, Available-for-sale [Line Items]    
Debt instrument, proportion of debt associated with return 36.30% 32.10%
Other debt securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost basis $ 0.0 $ 6.3
Accumulated unrealized gains (losses) 0.0 0.0
Fair value $ 0.0 $ 6.3