Significant Accounting Policies (Impact of Adoption of ASC 842 on Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease - right of use asset	$ 3,729	$ 4,267
Operating lease liabilities, current	775	964
Operating lease liabilities, non-current	3,067	3,432
Deferred rent	$ 277	129	$ 38
Adjustments Due to the Adoption of ASC 842 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease - right of use asset		4,267
Operating lease liabilities, current		964
Operating lease liabilities, non-current		$ 3,432