Assets and Liabilities Measured at Fair Value (Narrative) (Details) - LendingTree	Jun. 06, 2017 $ / shares $ / unit shares
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Number of shares purchased (in shares) | shares	450,000
Variable forward
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Variable forward contract, term	2 years
Variable forward contract (in 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