Derivative Instruments (Impact of Derivative Instruments on Borrowing Costs) (Details)	Sep. 30, 2020
Derivative [Line Items]
Increase of derivative instruments on borrowing costs	0.26%
UPC Holding
Derivative [Line Items]
Increase of derivative instruments on borrowing costs	0.24%
Telenet
Derivative [Line Items]
Increase of derivative instruments on borrowing costs	0.31%