Leases - Schedule of Right-of-Use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Right-of-use asset	$ 963	$ 1,483
Lease liabilities	1,003	1,519
Del Mar, CA [Member]
Lessee Lease Description [Line Items]
Right-of-use asset	613	745
Lease liabilities	641	745
Burlingame, CA [Member]
Lessee Lease Description [Line Items]
Right-of-use asset	99	392
Lease liabilities	109	429
Edwardsville, IL [Member]
Lessee Lease Description [Line Items]
Right-of-use asset	251	346
Lease liabilities	$ 253	$ 345