v3.10.0.1
Investments (Schedules) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Investment [Line Items]      
Equity $ 3,947.0 $ 4,324.6  
Fair value 1,174.8 2,315.3  
Cost 0.0 31.5  
Total 5,121.8 6,671.4  
Share of results of affiliates, net (8.7) (95.2) $ (111.6)
VodafoneZiggo JV      
Investment [Line Items]      
Equity 3,761.5 4,162.8  
Share of results of affiliates, net 11.4 (70.1) 0.0
Summarized Financial Condition      
Revenue 4,602.2 4,512.5 0.0
Loss before income taxes (467.8) (362.9)  
Net loss (91.6) (259.3)  
Current assets 1,099.6 823.4  
Total assets 22,155.7 24,076.8  
Total assets 23,255.3 24,900.2  
Current liabilities 2,812.3 2,631.7  
Long-term liabilities 14,751.5 16,110.4  
Owners’ / Partners' equity 5,691.5 6,158.1  
Total liabilities and owners’ equity 23,255.3 24,900.2  
Other      
Investment [Line Items]      
Equity 185.5 161.8  
Fair value 298.2 244.7  
Share of results of affiliates, net (20.1) (25.1) (111.6)
ITV plc (ITV) — subject to re-use rights      
Investment [Line Items]      
Fair value 634.2 892.0  
ITI Neovision S.A. (ITI Neovision)      
Investment [Line Items]      
Fair value 125.4 161.9  
Lions Gate Entertainment Corp (Lionsgate)      
Investment [Line Items]      
Fair value 77.5 163.9  
Casa Systems, Inc. (Casa)      
Investment [Line Items]      
Fair value 39.5 76.3  
Sumitomo Corporation (Sumitomo)      
Investment [Line Items]      
Fair value 0.0 776.5  
All3Media      
Summarized Financial Condition      
Revenue 892.3 769.8 649.1
Loss before income taxes (46.8) (49.3) (96.6)
Net loss (58.6) (51.6) $ (91.0)
Current assets 532.6 409.4  
Total assets 681.0 748.0  
Total assets 1,213.6 1,157.4  
Current liabilities 458.0 389.1  
Long-term liabilities 766.2 718.8  
Owners’ / Partners' equity 2.7 46.6  
Noncontrolling interests (13.3) 2.9  
Total liabilities and owners’ equity $ 1,213.6 $ 1,157.4