Segment Reporting (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) market country	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) market country	Jun. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Revenues | $	$ 5,074.1	$ 4,566.5	$ 9,662.1	$ 9,083.4
Threshold percentage used to determine reportable segments using one of three criteria of revenue, operating cash flow or total assets	10.00%		10.00%
Performance measures, percentage of reportable segment revenue and operating cash flow presented			100.00%
Total European Operations Division [Member]
Segment Reporting Information [Line Items]
Number of European countries in operating segment (in countries) | country	12		12
Telenet and Liberty Puerto Rico [Member]
Segment Reporting Information [Line Items]
Percentage of minority interest revenues and expenses included in net earnings attributable to noncontrolling interest			100.00%
Mobile Interconnect [Member]
Segment Reporting Information [Line Items]
Revenues | $	$ 77.7	53.1	$ 142.7	107.5
SOHO Cable Subscription [Member]
Segment Reporting Information [Line Items]
Revenues | $	$ 93.8	$ 67.4	$ 180.6	$ 130.0
Consumer and Business-to-Business Services [Member] | Latin America and the Caribbean [Member]
Segment Reporting Information [Line Items]
Number of countries in which entity provides services | country	18		18
Consumer and Business-to-Business Services [Member] | Outside of Latin America and Caribbean [Member]
Segment Reporting Information [Line Items]
Number of countries in which entity provides services | country	1		1
Cable & Wireless Communications Limited (CWC) [Member] | Sub-Sea Networks [Member]
Segment Reporting Information [Line Items]
Number of markets | market	30		30