v3.10.0.1
Equity (Share Repurchases Programs) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jul. 31, 2018
Class of Stock [Line Items]        
Distributable reserves recognized   $ 22,700,000,000    
Authorized amount       $ 500,000,000.0
Stock repurchase, remaining authorized amount $ 566,200,000      
Liberty Global Shares        
Class of Stock [Line Items]        
Total cost for stock purchased pursuant to repurchase programs $ 2,010,000,000.0 $ 2,894,700,000 $ 2,068,000,000.0  
Liberty Global Shares | Class A        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares) 15,649,900 34,881,510 32,387,722  
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 29.67 $ 33.73 $ 32.26  
Liberty Global Shares | Class C        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares) 54,211,059 52,523,651 31,557,089  
Average price paid per share pursuant to repurchase programs (in dollars per shares) $ 28.51 $ 32.71 $ 32.43  
LiLAC Shares        
Class of Stock [Line Items]        
Total cost for stock purchased pursuant to repurchase programs   $ 53,500,000 $ 21,500,000  
LiLAC Shares | Class A        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares)   2,062,233 720,800  
Average price paid per share pursuant to repurchase programs (in dollars per shares)   $ 22.84 $ 20.65  
LiLAC Shares | Class C        
Class of Stock [Line Items]        
Shares purchased pursuant to repurchase programs (in shares)   285,572 313,647  
Average price paid per share pursuant to repurchase programs (in dollars per shares)   $ 22.25 $ 21.19