Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Details)

v3.10.0.1
Stockholders' Equity (Details)
$ / shares in Units, $ in Millions
 1 Months Ended 12 Months Ended
May 18, 2018
shares
Oct. 03, 2017
USD ($)
shares
Mar. 31, 2017
USD ($)
May 18, 2016
USD ($)
$ / shares
Jan. 09, 2015
shares
Dec. 10, 2014
$ / shares
Nov. 04, 2014
shares
Oct. 29, 2014
May 31, 2016
shares
Dec. 31, 2018
USD ($)
Vote
item
$ / shares
$ / item
shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
shares
Broadband Spin-Off Distribution Ratio               0.25        
Shares issued during period             85,761,332          
Liberty Interactive                        
Number of shares purchased                 42,700,000      
Non-voting economic ownership percentage                       23.50%
Series A common stock                        
Common Stock, Par or Stated Value Per Share | $ / shares                   $ 0.01 $ 0.01  
Number Of Votes | Vote                   1    
Common Stock, Capital Shares Reserved for Future Issuance                   393,000    
Series B common stock                        
Common Stock, Par or Stated Value Per Share | $ / shares                   $ 0.01 0.01  
Number Of Votes | Vote                   10    
Common Stock Shares Received In Exchange For One Share Of Series B | item                   1    
Series C common stock                        
Subscription Rights Distribution Ratio           0.20            
Proceeds from Issuance of Common Stock | $       $ 4,400.0                
Shares issued during period 78,300,000       17,277,224              
Common Stock, Par or Stated Value Per Share | $ / shares       $ 0.01           $ 0.01 $ 0.01  
Purchase price (in dollars per share) | $ / shares       $ 56.23   $ 40.36            
Discount percentage for holders to acquire shares enabled by subscription rights           20.00%            
Number of trading days of volume weighted average trading price used for calculating discount for holders to acquire shares enabled by subscription rights           20 days            
Number Of Votes | Vote                   0    
Common Stock, Capital Shares Reserved for Future Issuance                   2,400,000    
Call Option | Series C common stock | Zero-strike call option                        
Derivative underlying share amount   527,156               0 0 704,908
Derivative, Price Risk Option Strike Price | $ / item                   90.54    
Derivative premium paid | $   $ 47.7               $ 142.8 $ 149.4 $ 47.9
Derivative settlement proceeds | $     $ 50.0             $ 146.5 $ 155.7