Organization and Summary of Significant Accounting Policies - Adoption of ASC 842 - General information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use asset	$ 4,300	$ 4,877	$ 4,877
Operating lease liabilities	$ 5,956		$ 7,000
Deferred rent				$ 2,404