Share-based Compensation (Summary of Stock-Based Compensation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 56.6	$ 54.4	$ 128.0	$ 109.5
Operating expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1.4	3.6	2.1	4.9
SG&A expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	55.2	50.8	125.9	104.6
Other Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	0.6	1.2	1.3	2.6
Liberty Global Group [Member] | Operating expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1.1	3.2	1.8	4.0
Liberty Global Group [Member] | SG&A expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	53.9	49.3	125.7	101.4
LiLAC Group [Member] | Operating expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	0.3	0.4	0.3	0.9
LiLAC Group [Member] | SG&A expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1.3	1.5	0.2	3.2
Parent Company [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	53.6	45.4	121.1	96.2
Parent Company [Member] | PSUs / PGUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	28.5	23.2	70.6	43.8
Parent Company [Member] | Other Share-Based Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	25.1	22.2	50.5	52.4
Telenet [Member] | Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2.4	$ 7.8	$ 5.6	$ 10.7