Earnings or Loss per Share Schedules (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net earnings (loss) attributable to Liberty Global shareholders	$ (674.3)	$ 101.4	$ (994.5)	$ (267.7)
Liberty Global Group [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net earnings (loss) attributable to Liberty Global shareholders	$ (636.6)	$ 204.2	$ (929.5)	$ (126.4)
Weighted average ordinary shares outstanding, Basic (in shares)	853,612,217	892,530,351	871,936,668	868,011,483
Incremental shares attributable to the assumed exercise of outstanding options, SARs and PSARs and the release of share units upon vesting (treasury stock method)		8,155,954
Weighted average ordinary shares outstanding, Diluted (in shares)	853,612,217	900,686,305	871,936,668	868,011,483
LiLAC Group [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net earnings (loss) attributable to Liberty Global shareholders	$ (37.7)	$ (102.8)	$ (65.0)	$ (141.3)
Weighted average ordinary shares outstanding, Basic (in shares)	172,074,934	50,357,803	172,410,613	47,145,780
Weighted average ordinary shares outstanding, Diluted (in shares)	172,074,934	50,357,803	172,410,613	47,145,780