Acquisitions (Pro Forma Information) (Details) - Ziggo and Choice Acquisition [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Business Acquisition [Line Items]
Revenue	$ 4,581.5	$ 5,175.8	$ 9,120.5	$ 10,293.3
Liberty Global Group	(464.8)	(444.4)	(1,000.4)	(662.6)
Intergroup Eliminations [Member]
Business Acquisition [Line Items]
Revenue	0.0	0.0	0.0	(0.1)
Liberty Global Group [Member]
Business Acquisition [Line Items]
Revenue	4,255.1	4,847.7	8,484.2	9,643.7
Liberty Global Group	$ (457.3)	$ (452.0)	$ (1,025.4)	$ (603.3)
Basic and diluted loss attributable to Liberty Global shareholders per share:	$ (0.53)	$ (0.49)	$ (1.13)	$ (0.73)
Liberty Global Group [Member] | Continuing Operations [Member]
Business Acquisition [Line Items]
Revenue	$ 4,255.1	$ 4,847.7	$ 8,484.2	$ 9,617.1
Liberty Global Group [Member] | Discontinued Operations [Member]
Business Acquisition [Line Items]
Revenue	0.0	0.0	0.0	26.6
LiLAC Group [Member]
Business Acquisition [Line Items]
Revenue	326.4	328.1	636.3	649.7
Liberty Global Group	$ (7.5)	$ 7.6	$ 25.0	$ (59.3)