Shareholders' Equity and Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 22, 2018
Earnings Per Share Reconciliation [Abstract]
Net Income		$ 8,817	$ 5,931	$ 17,978	$ 11,905
Weighted average shares outstanding (in shares)	[1]	24,109	21,331	22,745	21,320
Effect of stock options (in shares)		224	143	179	147
Stock units for deferred compensation plan for non-employee directors (in shares)		126	119	125	119
Performance share units (in shares)		51	54	50	57
Weighted average shares outstanding for calculation of diluted earnings per share (in shares)		24,510	21,647	23,099	21,643
Net income per common share [Abstract]
Basic (in dollars per share)	[1]	$ 0.37	$ 0.28	$ 0.79	$ 0.56
Diluted (in dollars per share)		$ 0.36	$ 0.27	$ 0.78	$ 0.55
Common Stock [Member]
Share Repurchase Plan [Abstract]
Share repurchase plan percentage of shares authorized to be repurchased						5.00%
Stock Options [Member]
Antidilutive Securities [Abstract]
Antidilutive shares excluded from computation of diluted loss per share (in shares)		0	0	0	0

[1] Basic net income per common share includes weighted average common shares outstanding during the period and participating share awards.