Equity (Share Repurchases Programs) (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Feb. 13, 2020
Class of Stock [Line Items]        
Distributable reserves recognized   $ 20,700.0    
Stock repurchase, remaining authorized amount $ 66.4      
Remaining authorized for share repurchases $ 2,700.0      
Class A        
Class of Stock [Line Items]        
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 27.50      
Shares repurchased (in shares) 24,002,262      
Class C        
Class of Stock [Line Items]        
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 27.00      
Shares repurchased (in shares) 75,420,009      
Liberty Global Shares        
Class of Stock [Line Items]        
Total cost for stock purchased pursuant to repurchase programs $ 3,220.2 $ 2,010.0 $ 2,894.7  
Liberty Global Shares | Class A        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares) 24,348,562 15,649,900 34,881,510  
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 27.61 $ 29.67 $ 33.73  
Liberty Global Shares | Class C        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares) 95,395,291 54,211,059 52,523,651  
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 26.64 $ 28.51 $ 32.71  
LiLAC Shares        
Class of Stock [Line Items]        
Total cost for stock purchased pursuant to repurchase programs     $ 53.5  
LiLAC Shares | Class A        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares)     2,062,233  
Average price paid per share pursuant to repurchase programs (in dollars per shares)     $ 22.84  
LiLAC Shares | Class C        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares)     285,572  
Average price paid per share pursuant to repurchase programs (in dollars per shares)     $ 22.25  
Subsequent Event        
Class of Stock [Line Items]        
Additional repurchase of shares (in shares)       1,000,000,000.0