Derivative Financial Instruments (Schedule of Offsetting of Derivative Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Offsetting of Derivative Assets [Line Items]
Gross Amounts of Recognized Assets	$ 859	$ 786
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Assets Presented on the Condensed Consolidated Balance Sheets	859	786
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments	(165)	(362)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged	0	0
Net Amount	694	424
J.P. Morgan Chase
Offsetting of Derivative Assets [Line Items]
Gross Amounts of Recognized Assets	429
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0
Net Amounts Of Assets Presented on the Condensed Consolidated Balance Sheets	429
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments	(110)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged	0
Net Amount	319
Bank of America
Offsetting of Derivative Assets [Line Items]
Gross Amounts of Recognized Assets	156	323
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Assets Presented on the Condensed Consolidated Balance Sheets	156	323
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments	0	(64)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged	0	0
Net Amount	156	259
Wells Fargo
Offsetting of Derivative Assets [Line Items]
Gross Amounts of Recognized Assets	274	463
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Assets Presented on the Condensed Consolidated Balance Sheets	274	463
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments	(55)	(298)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged	0	0
Net Amount	$ 219	$ 165