Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Narrative) (Details)

v3.20.4
Stockholders' Equity (Narrative) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2020
USD ($)
Vote
shares
Dec. 31, 2019
USD ($)
shares
Dec. 31, 2018
USD ($)
shares
May 23, 2018
shares
Mar. 09, 2018
Jun. 02, 2015
shares
Class of Stock [Line Items]            
Capital stock authorized for issuance       8,200,000,000   9,015,000,000
Common Stock, Capital Shares Reserved for Future Issuance 43,800,000     8,150,000,000   8,965,000,000
Preferred Stock, Capital Shares Reserved for Future Issuance       50,000,000    
Common Class A            
Class of Stock [Line Items]            
Number of votes | Vote 1          
Share received in exchange 1          
Common stock, shares authorized 4,000,000,000 4,000,000,000        
Common Stock, Shares, Issued 382,165,550 386,691,461        
Common Stock, Shares, Outstanding 382,165,550 386,691,461        
Common Stock, Capital Shares Reserved for Future Issuance       4,000,000,000    
Stock Repurchased and Retired During Period, Shares 6,521,782 24,329,610 43,080,787      
Stock Repurchased and Retired During Period, Value | $ $ 70.0 $ 392.0 $ 988.0      
Common Class A | Stock Option            
Class of Stock [Line Items]            
Common Stock, Capital Shares Reserved for Future Issuance 40,600,000          
Common Class A | Liberty Ventures common stock            
Class of Stock [Line Items]            
Spilt-Off redemption ratio         1  
Common Stock, Capital Shares Reserved for Future Issuance           400,000,000
Common Class B            
Class of Stock [Line Items]            
Number of votes | Vote 10          
Common stock, shares authorized 150,000,000 150,000,000        
Common Stock, Shares, Issued 29,366,492 29,278,424        
Common Stock, Shares, Outstanding 29,366,492 29,278,424        
Common Stock, Capital Shares Reserved for Future Issuance       150,000,000    
Common Class B | Stock Option            
Class of Stock [Line Items]            
Common Stock, Capital Shares Reserved for Future Issuance 3,200,000          
Common Class B | Liberty Ventures common stock            
Class of Stock [Line Items]            
Spilt-Off redemption ratio         1  
Common Stock, Capital Shares Reserved for Future Issuance           15,000,000
Common Class C            
Class of Stock [Line Items]            
Common stock, shares authorized 4,000,000,000          
Common Stock, Shares, Issued 0          
Common Stock, Shares, Outstanding 0          
Common Stock, Capital Shares Reserved for Future Issuance       4,000,000,000    
Common Class C | Liberty Ventures common stock            
Class of Stock [Line Items]            
Common Stock, Capital Shares Reserved for Future Issuance           400,000,000