Derivative Financial Instruments (Summary Of Location And Amounts Of Derivative Fair Values In The Consolidated Balance Sheets) (Details) - Non-hedging derivatives [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative Fair Values	$ 1,306	$ 1,323
Total Return Swap [Member] | Other liabilities [Member]
Derivative [Line Items]
Derivative Fair Values	801	1,200
Option contracts [Member] | Other liabilities [Member]
Derivative [Line Items]
Derivative Fair Values	$ 505	$ 123