Stock-Based Compensation (Stock Option Plans) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, Beginning of Period, Shares	4,500	21,500
Options Exercised, Shares	(350)	0
Balance, End of Period, Shares	4,150	21,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Balance, Beginning of Period, Weighted Avg. Exercise Price	$ 22.91	$ 23.57
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	22.91	0.00
Balance, End of Period, Weighted Avg. Exercise Price	$ 22.91	$ 23.57