ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications from Accumulated Ohter Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 176,624	$ 207,163
Total other comprehensive loss, net of tax	0	(544)
Ending balance	178,255	176,624
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	0	544
Ending balance	0	0
Unrealized gain on available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Total reclassified and recognized in net loss, net of tax	$ 0	$ (544)