LEASES - NARRATIVE (Details) $ in Thousands		3 Months Ended
	Mar. 12, 2020 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020	Jan. 31, 2020 ft²
Leases
Operating Lease, Initial Direct Cost Expense, over Term	$ 300
Operating lease liabilities		$ 2,716	$ 3,059
Right-of-use assets		1,439	$ 1,607
Operating Lease, Weighted Average Discount Rate, Percent					3.50%
Prepaid Expenses and Other Current Assets [Member]
Leases
Operating Lease, Initial Direct Cost Expense, over Term		100
Other Assets [Member]
Leases
Operating Lease, Initial Direct Cost Expense, over Term		$ 100
San Francisco California Facility
Leases
Area | ft²						5,000
Operating lease liabilities				$ 600
Right-of-use assets				$ 600
Operating Lease, Weighted Average Discount Rate, Percent				3.50%