Summary of Significant Accounting Policies (Schedule of Differences Between Book Value and Tax Basis of Net Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Financial statement basis of net assets	$ 6,637	$ 7,248	$ 7,892	$ 9,196	$ 9,911	$ 10,501