OTHER (EXPENSE) INCOME, NET - Components of Other (Expense) Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Income and Expenses [Abstract]
Interest and investment income	$ 100	$ 71	$ 174	$ 383
Income tax (benefit) expense	(174)	91	(301)	(115)
Other non-operating income	0	0	0	2
Total other (expense) income, net	$ (74)	$ 162	$ (127)	$ 270