Stock Plans (Schedule Of Compensation Cost For Share-Based Payment Arrangements, Allocation Of Share-Based Compensation Costs By Plan) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Non-Vested Equity Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 330,000	$ 225,000	$ 207,000
Non-Vested Equity Awards [Member] | Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	174,000	107,000	134,000
Non-Vested Equity Awards [Member] | Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	141,000	74,000	40,000
Non-Vested Equity Awards [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	15,000	44,000	33,000
Restricted Stock And Stock-Settled Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 200,000	$ 0	$ 0