Segment Reporting (Capital Expenditures of Reportable Segments) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	$ 1,850.4	$ 1,631.7
Assets acquired under capital-related vendor financing arrangements	(1,187.9)	(1,164.1)
Assets acquired under capital leases	(46.5)	(97.9)
Changes in current liabilities related to capital expenditures	181.8	218.3
Third-party payments	855.1	782.9
Proceeds received for transfers to related parties	(57.3)	(194.9)
Total capital expenditures, net	797.8	588.0
U.K./Ireland
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	1,040.1	970.7
Belgium
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	355.2	288.4
Switzerland
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	105.2	96.5
Central and Eastern Europe
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	71.9	117.0
Central and Corporate
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	278.0	159.1
VodafoneZiggo JV
Segment Reporting Information [Line Items]
Property and equipment additions - VodafoneZiggo JV	$ 476.6	$ 444.5

Assets Acquired Under Capital-Related Vendor Financing Arrangements

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Equity Method Investment, Summarized Financial Information, Payment to Acquire Property, Plant and Equipment

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The increase during the period in capital lease obligations due to entering into new capital leases.

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Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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