BALANCE SHEETS DETAILS Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expense		$ 816
Contract with Customer, Asset, after Allowance for Credit Loss, Current	$ 10,172	11,623
Other Assets, Current	195	171
Prepaid expenses and other current assets	11,213	$ 12,610
Prepaid Expense, Current	$ 846