Stock Option Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options exercised	28,538	65,161	77,600
Proceeds from stock options exercised	$ 253,000	$ 1,200,000	$ 976,000
Options exercised during the period, intrinsic value	$ 722,000	$ 1,100,000	$ 911,000
Options granted	0	0	0
2000 Stock Option Plan [Member]
Shares authorized to grant options	141,462
Options granted	0	0
Equity Compensation Plan [Member]
Shares authorized to grant options	352,741