DISCONTINUED OPERATIONS (Details-Disposal Groups) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended			12 Months Ended
	Dec. 04, 2019	Jan. 31, 2016	Dec. 31, 2013	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Jul. 21, 2019	May 31, 2017	Jun. 06, 2012
DISCONTINUED OPERATIONS
Loss Contingency, Damages Sought, Value			$ 61,000
Assets				$ 1,016,620				$ 947,969
Revenue and net income (loss) of discontinued operations
Revenue				0		$ 0
Loss before income taxes				(6,102)		(1,344)
Income tax benefit				1,527		282
Loss from discontinued operations				(4,575)		$ (1,062)
Assets and liabilities of facilities reported as discontinued operations
Annual interest rate on convertible senior notes										0.625%
Lending Tree Loans | Discover
DISCONTINUED OPERATIONS
Asset purchase agreement proceeds from sale											$ 55,900
Home Loan Center, Inc.
DISCONTINUED OPERATIONS
Assets									$ 11,200
Assets and liabilities of facilities reported as discontinued operations
Cash									$ 5,900
Dividends		$ 40,000
Discontinued Operations, Disposed of by Means Other than Sale [Member] | Home Loan Center, Inc.
Assets and liabilities of facilities reported as discontinued operations
Loss recognized					$ 5,500
Net gain related to removal of HLC					4,500
Recognition of liability					$ 10,000
Discontinued Operations, Disposed of by Means Other than Sale [Member] | Obligation to Repurchase Receivables Sold | Lending Tree Loans
Assets and liabilities of facilities reported as discontinued operations
Current liabilities				(36,000)
Discontinued Operations, Disposed of by Means Other than Sale [Member] | Discontinued Operations | Minimum | Obligation to Repurchase Receivables Sold | Lending Tree Loans
Assets and liabilities of facilities reported as discontinued operations
Loss Contingency, Estimate of Possible Loss				0
Discontinued Operations, Disposed of by Means Other than Sale [Member] | Discontinued Operations | Maximum | Obligation to Repurchase Receivables Sold | Lending Tree Loans
Assets and liabilities of facilities reported as discontinued operations
Loss Contingency, Estimate of Possible Loss				40,000
Pending Settlement | Discontinued Operations, Disposed of by Means Other than Sale [Member] | Discontinued Operations | Obligation to Repurchase Receivables Sold | Lending Tree Loans
DISCONTINUED OPERATIONS
Settlement value of indemnification claim and other miscellaneous items				$ 36,000
Lehman Brothers Holdings, Inc. Demand Letter
DISCONTINUED OPERATIONS
Loss Contingency, Damages Sought, Value	$ 44,700						$ 40,200