OTHER LONG-TERM ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
OTHER LONG-TERM ASSETS
Other long-term assets	$ 0	$ 8,000
Prepaid expenses, long-term portion	3,166	4,419
Deposit on purchase of a business	867	2,154
Total other long-term assets, net	$ 4,033	$ 14,573