Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
Assets and Liabilities Measured at Fair Value (Narrative) (Details)
$ / shares in Units, $ in Millions
 1 Months Ended
Jun. 06, 2017
$ / shares
$ / unit
shares
Jun. 30, 2018
USD ($)
shares
Mar. 31, 2019
USD ($)
shares
Exchangeable Senior Debentures | 1.75% Exchangeable Debentures | Indemnification obligation      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Indemnity obligation recorded | $     $ 281.3
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)     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)   417,759  
Value of shares repurchased | $   $ 457.0  
Indemnification payment | $   $ 133.0  
LendingTree      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Number of shares purchased (in shares) 450,000    
LendingTree | Variable forward      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Variable forward contract, term 2 years    
Variable forward contract (in shares) 642,850    
Variable forward contract, closing price (in dollars per share) | $ / shares $ 170.70    
Variable forward contract, floor price (in dollars per share) | $ / unit 128.03    
Variable forward contract, cap price (in dollars per share) | $ / unit 211.67