Segment Reporting (Performance Measures) (Schedule) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 2,875.8	$ 2,868.0
Adjusted OIBDA	1,150.3	1,183.3
VodafoneZiggo JV
Segment Reporting Information [Line Items]
Revenue	1,097.1	1,093.9
Adjusted OIBDA	502.8	493.8
Operating Segments
Segment Reporting Information [Line Items]
Adjusted OIBDA	1,150.3	1,183.3
Operating Segments \| U.K./Ireland
Segment Reporting Information [Line Items]
Revenue	1,620.6	1,661.3
Adjusted OIBDA	655.4	692.2
Operating Segments \| Belgium
Segment Reporting Information [Line Items]
Revenue	718.1	711.9
Adjusted OIBDA	331.6	339.0
Operating Segments \| Switzerland
Segment Reporting Information [Line Items]
Revenue	316.8	316.0
Adjusted OIBDA	134.1	156.3
Operating Segments \| Central and Eastern Europe
Segment Reporting Information [Line Items]
Revenue	119.1	119.1
Adjusted OIBDA	54.3	53.7
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Revenue	101.2	60.7
Adjusted OIBDA	(25.1)	(59.3)
Intersegment eliminations (a)
Segment Reporting Information [Line Items]
Revenue	0.0	(1.0)
Adjusted OIBDA	$ 0.0	$ 1.4

Adjusted Operating Income (Loss) before Depreciation and Amortization

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Amount of revenue from sale of product and rendering of service reported by equity method investee.

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-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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