Equity (Changes in Share Capital) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 6,393.0	$ 14,732.0	$ 10,174.3
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	(2,010.0)	(2,948.2)	(2,089.5)
Impact of acquisitions			5,941.9
Other	(17.4)	(162.1)	(178.7)
Ending balance	4,148.3	6,393.0	14,732.0
Liberty Global Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	8.9	8.5
Impact of the LiLAC Transaction	0.0	0.0
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	(0.8)	(0.6)
Impact of acquisitions		1.1
Other		(0.1)
Ending balance	8.1	8.9	8.5
Liberty Global Shares \| Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2.5	2.5
Impact of the LiLAC Transaction	0.0	0.0
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	(0.3)	(0.3)
Impact of acquisitions		0.3
Other		0.0
Ending balance	2.2	2.5	2.5
Liberty Global Shares \| Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.1	0.1
Impact of the LiLAC Transaction	0.0	0.0
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	0.0	0.0
Impact of acquisitions		0.0
Other		0.0
Ending balance	0.1	0.1	0.1
Liberty Global Shares \| Class C
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	6.3	5.9
Impact of the LiLAC Transaction	0.0	0.0
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	(0.5)	(0.3)
Impact of acquisitions		0.8
Other		(0.1)
Ending balance	5.8	6.3	5.9
LiLAC Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.7	0.4
Impact of the LiLAC Transaction	(1.7)	1.2
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	0.0	0.0
Impact of acquisitions		0.1
Other		0.0
Ending balance	0.0	1.7	0.4
LiLAC Shares \| Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.5	0.1
Impact of the LiLAC Transaction	(0.5)	0.4
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	0.0	0.0
Impact of acquisitions		0.0
Other		0.0
Ending balance	0.0	0.5	0.1
LiLAC Shares \| Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.0	0.0
Impact of the LiLAC Transaction	0.0	0.0
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	0.0	0.0
Impact of acquisitions		0.0
Other		0.0
Ending balance	0.0	0.0	0.0
LiLAC Shares \| Class C
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.2	0.3
Impact of the LiLAC Transaction	(1.2)	0.8
Repurchase and cancellation of Liberty Global ordinary shares (note 13)	0.0	0.0
Impact of acquisitions		0.1
Other		0.0
Ending balance	$ 0.0	$ 1.2	$ 0.3

Amount of other increase (decrease) in additional paid in capital (APIC).

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Amount of increase in noncontrolling interest from a business combination.

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Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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