Annual report pursuant to Section 13 and 15(d)

Assets and Liabilities Measured at Fair Value (Narrative) (Details)

v3.19.3.a.u2
Assets and Liabilities Measured at Fair Value (Narrative) (Details)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Apr. 29, 2019
$ / shares
$ / unit
shares
Jun. 06, 2017
$ / shares
$ / unit
shares
Jun. 30, 2018
USD ($)
shares
Dec. 31, 2019
USD ($)
shares
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Indemnification payment | $       $ 0 $ 132,725 $ 0
Exchangeable Senior Debentures | 1.75% Exchangeable Debentures | Indemnification obligation            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Indemnity obligation recorded | $       $ 281,300    
Exchangeable Senior Debentures | 1.75% Exchangeable Debentures | Indemnification obligation | LI LLC            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Interest rate       1.75%    
Exchangeable instrument, shares outstanding (in shares) | shares       332,241    
Exchangeable Senior Debentures | 1.75% Exchangeable Debentures | Indemnification obligation | LI LLC | Qurate Retail            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Number of shares repurchased (in shares) | shares     417,759      
Value of shares repurchased | $     $ 457,000      
Indemnification payment | $     $ 132,700      
LendingTree            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Number of shares purchased (in shares) | shares   450,000        
Variable forward contract, term 3 years 2 years        
Variable forward contract (in shares) | shares 642,850 642,850        
Variable forward contract, closing price (in dollars per share) | $ / shares $ 376.35 $ 170.70        
Variable forward contract, floor price (in dollars per share) | $ / unit 0 128.03        
Variable forward contract, cap price (in dollars per share) | $ / unit 254.00 211.67