v3.10.0.1
Derivative Instruments (Basis Swaps, Interest Rate Caps and Collars) (Details)
$ in Millions
6 Months Ended
Jun. 30, 2018
USD ($)
Interest Rate Caps  
Derivative [Line Items]  
Notional amount of derivative $ 164.9
Interest Rate Collars  
Derivative [Line Items]  
Notional amount of derivative $ 662.7
Virgin Media | Basis Swaps  
Derivative [Line Items]  
Weighted average remaining life 15 days
UPC Holding | Basis Swaps  
Derivative [Line Items]  
Weighted average remaining life 15 days
Telenet | Basis Swaps  
Derivative [Line Items]  
Weighted average remaining life 15 days
Notional amount due from counterparty | Virgin Media | Basis Swaps  
Derivative [Line Items]  
Notional amount of derivative $ 4,587.5
Notional amount due from counterparty | UPC Holding | Basis Swaps  
Derivative [Line Items]  
Notional amount of derivative 1,975.0
Notional amount due from counterparty | Telenet | Basis Swaps  
Derivative [Line Items]  
Notional amount of derivative $ 1,600.0