Assets and Liabilities Measured at Fair Value (Narrative) (Details) - LendingTree	Apr. 29, 2019 $ / shares $ / unit shares	Jun. 06, 2017 $ / shares $ / unit shares
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