Debt and Capital Lease Obligations (Maturities of Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
2018 (remainder of year)	$ 4,159.4
2019	360.2
2020	346.4
2021	3,095.6
2022	777.6
2023	1,517.4
Thereafter	31,076.5
Total debt maturities	41,333.1
Deferred financing costs, discounts and premiums, net	(216.7)	$ (223.2)
Total debt	41,116.4
Current portion	4,150.2
Noncurrent portion	36,966.2
Virgin Media [Member]
Debt Instrument [Line Items]
2018 (remainder of year)	2,320.0
2019	133.8
2020	92.6
2021	1,402.6
2022	407.8
2023	979.6
Thereafter	11,960.2
Total debt maturities	17,296.6
Deferred financing costs, discounts and premiums, net	(61.6)
Total debt	17,235.0
Current portion	2,325.7
Noncurrent portion	14,909.3
Unitymedia [Member]
Debt Instrument [Line Items]
2018 (remainder of year)	389.2
2019	57.6
2020	3.7
2021	3.6
2022	3.4
2023	515.1
Thereafter	7,973.0
Total debt maturities	8,945.6
Deferred financing costs, discounts and premiums, net	(50.7)
Total debt	8,894.9
Current portion	445.2
Noncurrent portion	8,449.7
UPC Holding [Member]
Debt Instrument [Line Items]
2018 (remainder of year)	542.0
2019	79.4
2020	20.3
2021	20.0
2022	15.3
2023	9.9
Thereafter	6,534.9
Total debt maturities	7,221.8
Deferred financing costs, discounts and premiums, net	(52.4)
Total debt	7,169.4
Current portion	616.8
Noncurrent portion	6,552.6
Telenet [Member]
Debt Instrument [Line Items]
2018 (remainder of year)	710.4
2019	47.2
2020	13.9
2021	12.3
2022	12.6
2023	12.8
Thereafter	4,608.4
Total debt maturities	5,417.6
Deferred financing costs, discounts and premiums, net	(24.5)
Total debt	5,393.1
Current portion	736.7
Noncurrent portion	4,656.4
Other [Member]
Debt Instrument [Line Items]
2018 (remainder of year)	197.8
2019	42.2
2020	215.9
2021	1,657.1
2022	338.5
2023	0.0
Thereafter	0.0
Total debt maturities	2,451.5
Deferred financing costs, discounts and premiums, net	(27.5)
Total debt	2,424.0
Current portion	25.8
Noncurrent portion	$ 2,398.2