Equity (Changes in Share Capital) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 4,148.3	$ 6,393.0	$ 14,732.0
Repurchase and cancellation of Liberty Global Shares	(3,220.2)	(2,010.0)	(2,948.2)
Ending balance	13,198.6	4,148.3	$ 6,393.0
Liberty Global Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	8.9
Impact of the Split-off Transaction	0.0
Repurchase and cancellation of Liberty Global Shares	(0.8)
Ending balance	8.1	8.9
Liberty Global Shares | Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2.5
Impact of the Split-off Transaction	0.0
Repurchase and cancellation of Liberty Global Shares	(0.3)
Ending balance	2.2	2.5
Liberty Global Shares | Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.1
Impact of the Split-off Transaction	0.0
Repurchase and cancellation of Liberty Global Shares	0.0
Ending balance	0.1	0.1
Liberty Global Shares | Class C
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	6.3
Impact of the Split-off Transaction	0.0
Repurchase and cancellation of Liberty Global Shares	(0.5)
Ending balance	5.8	6.3
LiLAC Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.7
Impact of the Split-off Transaction	(1.7)
Repurchase and cancellation of Liberty Global Shares	0.0
Ending balance	0.0	1.7
LiLAC Shares | Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.5
Impact of the Split-off Transaction	(0.5)
Repurchase and cancellation of Liberty Global Shares	0.0
Ending balance	0.0	0.5
LiLAC Shares | Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.0
Impact of the Split-off Transaction	0.0
Repurchase and cancellation of Liberty Global Shares	0.0
Ending balance	0.0	0.0
LiLAC Shares | Class C
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.2
Impact of the Split-off Transaction	(1.2)
Repurchase and cancellation of Liberty Global Shares	0.0
Ending balance	$ 0.0	$ 1.2