Stock-Based Compensation Plan (Summary Of Stock Option Activities) (Details) - Stock Options [Member] - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding at beginning of period, Number of Shares	1,428,255	1,189,255
Options granted, Number of Shares	190,500
Options exercised, Number of Shares	(60,875)
Options outstanding at end of period, Number of Shares	1,557,880	1,189,255
Options exercisable, Number of Shares	1,009,555	917,729
Options outstanding at beginning of period, Weighted Average Exercise Price	$ 16.31	$ 18.08
Options granted, Weighted Average Exercise Price	15.89
Options exercised, Weighted Average Exercise Price	8.44
Options outstanding at end of period, Weighted Average Exercise Price	16.57	18.08
Options exercisable, Weighted Average Exercise Price	$ 18.21	$ 16.92
Weighted average remaining term	4 years 6 months	4 years 8 months 12 days