Share-based Compensation (Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 99.8	$ 83.8	$ 163.2	$ 139.0
Other operating expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	7.6	1.6	8.8	2.3
SG&A expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	92.2	82.2	154.4	136.7
Liberty Global
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	81.4	75.4	138.2	127.6
Performance-based incentive awards | Liberty Global
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	14.4	21.6	38.4	49.3
Non-performance based incentive awards (b) | Liberty Global
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	59.4	47.8	84.8	66.1
Other (d)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	18.4	8.4	25.0	11.4
Other (d) | Liberty Global
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 7.6	$ 6.0	$ 15.0	$ 12.2