Investments In Securities and Fair Value (Schedule of Equity Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, Cost	$ 34,778	$ 33,570
Equity Securities, Estimated Fair Value	55,830	61,108
Common stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, Cost	34,778	33,570
Equity Securities, Estimated Fair Value	$ 55,830	$ 61,108