STOCKHOLDERS' EQUITY - AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 619,688	$ 354,944	$ 321,226
Ending balance	730,408	619,688	354,944
Net Unrealized Gains (Losses) From Available For Sale Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	319	322	(280)
Net unrealized gain (loss) on investments, net of tax	(180)	(3)	602
Ending balance	139	319	322
Unrealized Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1)	0	0
Foreign currency translation adjustments	29	(1)
Ending balance	28	(1)	0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	318	322	(280)
Net unrealized gain (loss) on investments, net of tax	(180)	(3)	602
Foreign currency translation adjustments	29	(1)
Ending balance	$ 167	$ 318	$ 322