Derivative Financial Instruments (Schedule of Offsetting of Derivative Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Offsetting of Derivative Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	$ 165	$ 368
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Liabilities Presented on the Condensed Consolidated Balance Sheets	165	368
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	0	6
J.P. Morgan Chase
Offsetting of Derivative Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	110	6
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Liabilities Presented on the Condensed Consolidated Balance Sheets	110	6
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments	(110)	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged	0	0
Net Amount	0	6
Bank of America
Offsetting of Derivative Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		64
Gross Amounts Offset on the Condensed Consolidated Balance Sheets		0
Net Amounts Of Liabilities Presented on the Condensed Consolidated Balance Sheets		64
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Financial Instruments		(64)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets: Cash Collateral Pledged		0
Net Amount		0
Wells Fargo
Offsetting of Derivative Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	55	298
Gross Amounts Offset on the Condensed Consolidated Balance Sheets	0	0
Net Amounts Of Liabilities Presented on the Condensed Consolidated Balance Sheets	55	298
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	$ 0	$ 0

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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