Selected Quarterly Information (Tables)

12 Months Ended

Dec. 31, 2012

Selected Quarterly Financial Information [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

	Year Ended December 31, 2012
	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating results:
Net interest income	$	19,147	$	19,008	$	19,100	$	21,145
Net interest income after provision for loan losses	19,087		19,008		18,990		21,123
Net income to common shareholders	16,476		18,847		18,353		18,330
Basic diluted net income per common share	$	0.33	$	0.35	$	0.34	$	0.34
Diluted net income per common share	$	0.33	$	0.35	$	0.34	$	0.34
Cash dividends declared per common share	$	0.28	$	0.29	$	0.29	$	0.29

	Year Ended December 31, 2011
	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating results:
Net interest income	$	12,731	$	15,033	$	14,559	$	16,972
Net interest income after provision for loan losses	12,481		14,833		14,259		16,851
Net income	10,280		13,594		1,532		14,406
Basic net income per common share	$	0.31	$	0.34	$	0.04	$	0.36
Diluted net income per common share	$	0.31	$	0.34	$	0.04	$	0.36
Cash dividends declared per common share	$	0.27	$	0.27	$	0.27	$	0.28

	Year Ended December 31, 2010
	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating results:
Net interest income	$	7,197	$	7,932	$	8,400	$	10,895
Net interest income after provision for loan losses	6,788		7,782		8,190		10,285
Net income to common shareholders	4,534		6,264		5,966		9,647
Basic net income per common share	$	0.32	$	0.41	$	0.35	$	0.41
Diluted net income per common share	$	0.30	$	0.38	$	0.33	$	0.40
Cash dividends declared per common share	$	0.23	$	0.23	$	0.25	$	0.27