Derivative Instruments (Impact of Derivative Instruments on Borrowing Costs) (Details)	Jun. 30, 2019
Derivative [Line Items]
Impact of derivative instruments on borrowing costs	(0.53%)
Virgin Media
Derivative [Line Items]
Impact of derivative instruments on borrowing costs	(0.49%)
UPC Holding
Derivative [Line Items]
Impact of derivative instruments on borrowing costs	(0.62%)
Telenet
Derivative [Line Items]
Impact of derivative instruments on borrowing costs	(0.61%)