Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Assets and Liabilities Measured at Fair Value (Narrative) (Details)
$ / shares in Units, $ in Millions
 3 Months Ended
Jun. 06, 2017
$ / shares
$ / unit
shares
Mar. 31, 2018
USD ($)
LendingTree    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Number of shares purchased | shares 450,000  
Variable forward | LendingTree    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Variable forward contract, term 2 years  
Variable forward contract, number of shares | 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  
1.75% Exchangeable Debentures | Indemnification obligation    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Indemnity obligation recorded | $   $ 281.3
LI LLC | 1.75% Exchangeable Debentures | Indemnification obligation    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Interest rate   1.75%
Qurate and LI LLC | 1.75% Exchangeable Debentures | Indemnification obligation    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Period in which entities will cooperate with and reasonably assist each other regarding the Purchase Offer   6 months