SEGMENT INFORMATION - Segmented Revenue Disaggregated by Service (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenue from contracts with customers	$ 343,650	$ 303,443
North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	324,132	281,994
Europe
Segment Reporting Information [Line Items]
Revenue from contracts with customers	19,518	21,449
Marketplace revenue | North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	258,776	220,500
Consumer connection revenue | North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	239,830	201,582
Service professional membership subscription revenue | North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	14,115	16,517
Other revenue | North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	4,831	2,401
Advertising and other revenue | North America
Segment Reporting Information [Line Items]
Revenue from contracts with customers	65,356	61,494
Advertising and other revenue | Europe
Segment Reporting Information [Line Items]
Revenue from contracts with customers	530	584
Consumer connection revenue | Europe
Segment Reporting Information [Line Items]
Revenue from contracts with customers	15,689	17,123
Service professional membership subscription revenue | Europe
Segment Reporting Information [Line Items]
Revenue from contracts with customers	$ 3,299	$ 3,742