Investments In Securities (Schedule of Equity Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, Cost	$ 32,019	$ 31,255
Equity Securities, Estimated Fair Value	55,065	48,489
Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, Cost	32,019	31,255
Equity Securities, Estimated Fair Value	$ 55,065	$ 48,489