RELATED PARTY TRANSACTIONS WITH IAC - Summary (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 29, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Taxes		$ 1,668	$ 7,483	$ 49,106
Net increase in IAC’s investment in HomeAdvisor				$ 46,339
IAC
Related Party Transaction [Line Items]
Cash transfers from IAC related to its centrally managed U.S. treasury management function, acquisitions and cash expenses paid by IAC on behalf of HomeAdvisor, net	$ (80,368)
Taxes	38,162
Interest income, net	656
Allocation of general and administrative expense	(4,789)		$ (4,800)
Net increase in IAC’s investment in HomeAdvisor	$ (46,339)