Basis of Presentation (Summary of stock options activity) (Details) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Shares
Outstanding at beginning of period (in shares)	26,400	125,950
Granted (in shares)	0	0
Exercised (in shares)	(13,650)	(55,250)
Forfeited (in shares)	(500)	(1,500)
Outstanding at end of period (in shares)	12,250	69,200
Options exercisable at end of period (in shares)	12,250	69,200
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 18.60	$ 24.08
Granted (in dollars per share)	0.00	0.00
Exercised (in dollars per share)	18.60	24.82
Forfeited (in dollars per share)	18.60	21.10
Outstanding at end of period (in dollars per share)	18.60	23.55
Options exercisable at end of period (in dollars per share)	$ 18.60	$ 23.55