Income Taxes (Schedule Of Historic Tax Credit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Loss on tax credit investment	$ (1,154)	$ (905)
Refundable state historic tax credit	2,843	2,117
Income tax benefit	(5,209)	(1,923)	$ (3,767)
Historic Structure In New York State [Member]
Income Tax Contingency [Line Items]
Loss on tax credit investment	(3,997)	(3,022)
Refundable state historic tax credit	2,843	2,117
Income tax benefit	1,869	1,413
Total HTC income	$ 715	$ 508