Share-based Compensation (Summary of Stock-Based Compensation) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended			9 Months Ended	3 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Continuing Operations [Member]	Sep. 30, 2013 Continuing Operations [Member]	Sep. 30, 2014 Continuing Operations [Member]	Sep. 30, 2013 Continuing Operations [Member]	Sep. 30, 2014 Discontinued Operations [Member]	Sep. 30, 2013 Discontinued Operations [Member]	Sep. 30, 2014 Discontinued Operations [Member]	Sep. 30, 2013 Discontinued Operations [Member]	Sep. 30, 2014 Operating expense	Sep. 30, 2013 Operating expense	Sep. 30, 2014 Operating expense	Sep. 30, 2013 Operating expense	Sep. 30, 2014 SG&A expense	Sep. 30, 2013 SG&A expense	Sep. 30, 2014 SG&A expense	Sep. 30, 2013 SG&A expense	Sep. 30, 2014 Other Stock Plan [Member]	Sep. 30, 2013 Other Stock Plan [Member]	Sep. 30, 2014 Other Stock Plan [Member]	Sep. 30, 2013 Other Stock Plan [Member]	Sep. 30, 2014 Parent Company [Member]	Sep. 30, 2013 Parent Company [Member]	Sep. 30, 2014 Parent Company [Member]	Sep. 30, 2013 Parent Company [Member]	Sep. 30, 2014 Parent Company [Member] Performance Shares [Member]	Sep. 30, 2013 Parent Company [Member] Performance Shares [Member]	Sep. 30, 2014 Parent Company [Member] Performance Shares [Member]	Sep. 30, 2013 Parent Company [Member] Performance Shares [Member]	Sep. 30, 2014 Parent Company [Member] Other Share-Based Incentive Awards [Member]	Sep. 30, 2013 Parent Company [Member] Other Share-Based Incentive Awards [Member]	Sep. 30, 2014 Parent Company [Member] Other Share-Based Incentive Awards [Member]	Sep. 30, 2013 Parent Company [Member] Other Share-Based Incentive Awards [Member]	Sep. 30, 2014 Virgin Media [Member] Virgin Media Replacement Awards [Member]	Sep. 30, 2013 Virgin Media [Member] Virgin Media Replacement Awards [Member]	Jun. 30, 2013 Virgin Media [Member] Virgin Media Replacement Awards [Member]	Sep. 30, 2014 Virgin Media [Member] Virgin Media Replacement Awards [Member]	Sep. 30, 2013 Virgin Media [Member] Virgin Media Replacement Awards [Member] SG&A expense	Jun. 30, 2013 Virgin Media [Member] Virgin Media Replacement Awards [Member] SG&A expense	Sep. 30, 2013 Telenet [Member]	Sep. 30, 2013 Telenet [Member] Telenet 2010 Specific Stock Option Plan [Member]	Sep. 30, 2014 Telenet [Member] Stock Compensation Plan [Member]	Sep. 30, 2013 Telenet [Member] Stock Compensation Plan [Member]	Sep. 30, 2014 Telenet [Member] Stock Compensation Plan [Member]	Sep. 30, 2013 Telenet [Member] Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 73.1	$ 98.7	$ 182.6	$ 219.4	$ 73.1	$ 98.2	$ 182.6	$ 217.9	$ 0	$ 0.5	$ 0	$ 1.5	$ 1.0	$ 0.8	$ 5.9	$ 10.7	$ 72.1	$ 97.4	$ 176.7	$ 207.2	$ 1.9	$ 2.1	$ 4.5	$ 2.4	$ 69.3	$ 91.7	$ 165.5	$ 164.6	$ 44.2	$ 12.6	$ 88.0	$ 24.5	$ 25.1	$ 79.1	$ 77.5	$ 140.1	$ 14.4	$ 61.6	$ 35.9	$ 45.8	$ 35.4	$ 27.5	$ 32.7	$ 6.2	$ 1.9	$ 4.9	$ 12.6	$ 52.4