Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Outstanding stock options (in shares)	0	0
Distributed earnings allocated to common stock	$ 4,686	$ 4,296
Undistributed earnings allocated to common stock	9,017	9,063
Net earnings allocated to common stock	13,703	13,359
Net earnings allocated to participating securities	115	152
Net income allocated to common stock and participating securities	$ 13,818	$ 13,511
Weighted average shares outstanding for basic earnings per common share	25,923,530	26,258,273	[1]
Dilutive effect of stock compensation (in shares)	0	0
Weighted average shares outstanding for diluted earnings per common share	25,923,530	26,258,273	[1]
Basic earnings per common share (in dollars per share)	$ 0.53	$ 0.51	[1]
Diluted earnings per common share (in dollars per share)	$ 0.53	$ 0.51	[1]

[1] *The computation of three months ended March 31, 2015 per common share data and shares outstanding gives retrospective recognition to a 10% stock dividend declared on July 22, 2015 and issued on August 14, 2015.