INFORMATION ABOUT REVENUE AND GEOGRAPHIC AREAS (Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	$ 220,807	$ 262,474	$ 639,738	$ 745,371
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	218,563	258,820	632,360	735,169
All other countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	2,244	3,654	7,378	10,202
Advertising
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	211,167	253,098	613,493	717,973
Transactions
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	4,412	3,074	11,019	9,528
Other services
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenue	$ 5,228	$ 6,302	$ 15,226	$ 17,870