BALANCE SHEET DETAILS - Other Assets, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other Assets, Net [Abstract]
Contract assets - long-term	$ 3,776	$ 4,596
Right-of-use ("ROU") assets	1,439	1,607
Deferred tax assets	2,659	2,659
Other assets	113	138
Total other assets	$ 7,987	$ 9,000