Derivative Instruments (Realized and Unrealized Gains (Losses) on Derivatives) (Schedule and Footnotes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Gain (loss) on derivative instruments, net	$ 1,052.0	$ (679.7)	$ 543.3	$ (61.2)
Cross-currency and interest rate derivative contracts
Derivative [Line Items]
Gain (loss) on derivative instruments, net	656.2	(548.3)	(116.8)	192.2
Foreign Exchange Contract [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	18.0	(16.3)	(10.8)	(24.4)
Liberty Global Group [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	1,097.4	(680.9)	733.4	(141.8)
Liberty Global Group [Member] | Cross-currency and interest rate derivative contracts
Derivative [Line Items]
Gain (loss) on derivative instruments, net	699.8	(547.7)	64.4	114.6
Liberty Global Group [Member] | Equity-related derivative instruments
Derivative [Line Items]
Gain (loss) on derivative instruments, net	378.4	(114.8)	671.6	(229.7)
Liberty Global Group [Member] | ITV Collar [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	308.3	(53.5)	513.7	(158.9)
Liberty Global Group [Member] | Sumitomo Collar [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	66.3	(61.8)	135.0	(71.9)
Liberty Global Group [Member] | Lionsgate Forward [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	3.3	0.0	22.0	0.0
Liberty Global Group [Member] | Other [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	0.5	0.5	0.9	1.1
Liberty Global Group [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	19.8	(18.1)	(1.9)	(27.4)
Liberty Global Group [Member] | Other
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(0.6)	(0.3)	(0.7)	0.7
LiLAC Group [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(45.4)	1.2	(190.1)	80.6
LiLAC Group [Member] | Cross-currency and interest rate derivative contracts
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(43.6)	(0.6)	(181.2)	77.6
LiLAC Group [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Gain (loss) on derivative instruments, net	$ (1.8)	$ 1.8	$ (8.9)	$ 3.0