ACQUISITIONS - Pro Forma Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Business Acquisition [Line Items]
Net revenue	$ 107,552
Net (loss) income from operations	2,541
DMS
Business Acquisition [Line Items]
Net revenue	96,803
Net (loss) income from operations	(212)
Aimtell, PushPros and Aramis
Business Acquisition [Line Items]
Net revenue	2,465
Net (loss) income from operations	457
Crisp Results
Business Acquisition [Line Items]
Net revenue	8,284
Net (loss) income from operations	$ 2,296