ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued expenses and other current liabilities
Accrued advertising expense	$ 64,932	$ 54,045
Accrued compensation and benefits	14,951	14,081
Accrued professional fees	3,727	1,869
Customer deposits and escrows	7,401	8,153
Contribution to LendingTree Foundation	3,333	3,333
Current lease liabilities	8,579	5,375
Other	11,741	14,340
Total accrued expenses and other current liabilities	$ 114,664	$ 101,196