Stock Option Plans (Summary of Status and Changes in Stock Option Plan) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Options outstanding, Beginning balance	239,400
Options granted	0	0	0
Options exercised	28,538	65,161	77,600
Options outstanding, Ending balance	210,862	239,400
Weighted Average Exercise Price
Options Outstanding, Weighted Average Exercise Price, Beginning balance	$ 7.78
Options Exercised, Weighted Average Exercise Price	8.86
Options Outstanding, Weighted Average Exercise Price, Ending balance	$ 7.63	$ 7.78
Weighted- Average Remaining Contractual Life (in years)
Options Outstanding, Weighted-Average Remaining Contractual Life	6 years 3 months 18 days
Aggregate Intrinsic Value
Options Outstanding, Aggregate Intrinsic Value	$ 3,994