Investments in Securities and Fair Value Investments in Securities (Schedule of Equity Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, cost	$ 22,981	$ 25,278
Common stocks	37,212	51,691
Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, cost	22,981	25,278
Common stocks	$ 37,212	$ 51,691