Stock Option Plans (Summary of Status and Changes in Stock Option Plan) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares
Options outstanding, Beginning balance	382,161
Options granted	0	0	0
Options exercised	77,600	186,059	118,823
Options outstanding, Ending balance		382,161
Options exercisable at year end	304,561
Weighted Average Exercise Price
Options Outstanding, Weighted Average Exercise Price, Beginning balance	$ 10.45
Options Exercised, Weighted Average Exercise Price	12.58
Options Outstanding, Weighted Average Exercise Price, Ending balance	$ 9.90	$ 10.45
Weighted- Average Remaining Contractual Life (in years)
Options Outstanding, Weighted-Average Remaining Contractual Life	7 years 4 months 24 days
Aggregate Intrinsic Value
Options Outstanding, Aggregate Intrinsic Value	$ 7,064,000