Earnings or Loss per Share (Narrative) (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
VM Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS	2,700,000
Liberty Global Group [Member] | Options, SARs, PSARs and RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS	24,300,000	55,500,000	49,300,000
Liberty Global Group [Member] | PSUs / PGUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS		7,300,000	8,900,000
Liberty Global Group [Member] | Obligations That May Be Settled in Cash or Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS		0	2,700,000
LiLAC Group [Member] | Options, SARs, PSARs and RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS		9,100,000	1,800,000
LiLAC Group [Member] | PSUs / PGUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Aggregate number of shares excluded from computation of EPS		1,300,000	400,000