Investment Securities (Details 5) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available for Sale, Amortized Cost
Within 1 year	$ 9	$ 2,999
After 1 year through 5 years	60,818	59,729
After 5 years through 10 years	116,308	100,658
Over 10 years	339,110	353,259
Total	516,245	516,645
Available for Sale, Estimated Fair Value
Within 1 year	10	3,003
After 1 year through 5 years	62,136	60,249
After 5 years through 10 years	119,089	100,833
Over 10 years	342,060	348,139
Total	$ 523,295	$ 512,224
Available for Sale, Weighted Average Rate
Within 1 year (as a percent)	0.13%	2.09%
After 1 year through 5 years (as a percent)	2.25%	2.32%
After 5 years through 10 years (as a percent)	2.02%	2.05%
Over 10 years (as a percent)	1.95%	1.97%
Total (as a percent)	2.00%	2.03%
Held-to-maturity, Amortized Cost
Within 1 year	$ 159	$ 651
After 1 year through 5 years	20,836	23,888
After 5 years through 10 years	37,548	50,078
Over 10 years	18,551	19,140
Total	77,094	93,757
Held-to-maturity, Estimated Fair Value
Within 1 year	159	651
After 1 year through 5 years	21,034	23,866
After 5 years through 10 years	38,293	50,344
Over 10 years	18,593	18,834
Total	$ 78,079	$ 93,695
Held-to-maturity, Weighted Average Rate
Within 1 year (as a percent)	1.73%	1.00%
After 1 year through 5 years (as a percent)	1.28%	1.52%
After 5 years through 10 years (as a percent)	1.79%	2.00%
Over 10 years (as a percent)	1.74%	1.82%
Total (as a percent)	1.64%	1.83%
Estimated fair value of debt securities have right to call or prepay the obligations	$ 28,900	$ 48,500
Estimated fair value of debt securities have right to call or prepay the obligations, schedule maturities of 1-5 years	3,100	15,500
Estimated fair value of debt securities have right to call or prepay the obligations, schedule maturities of 6-10 years	24,500	31,800
Estimated fair value of debt securities have right to call or prepay the obligations, scheduled maturities after ten years	$ 1,300	$ 1,200