Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Investment Securities Available-for-Sale
Gross Amortized cost	$ 296,645	$ 322,571
Gross Unrealized Gains	17,664	16,626
Gross Unrealized Losses	(49)	(66)
Fair Value	314,260	339,131
Investment Securities Held-to-Maturity
Gross Amortized cost	4,019	4,024
Gross Unrealized Losses	(594)	(690)
Fair Value	3,425	3,334
Available-for-Sale, Amortized cost
Within One Year	7,542	5,179
After 1 year but within 5 years	50,632	35,045
After 5 years but within 10 years	40,232	56,334
After 10 years	82,794	107,205
Mortgage-backed securities	115,445	118,808
Total	296,645	322,571
Available-for-Sale, Fair Value
Within One Year	7,640	5,272
After 1 year but within 5 years	53,731	36,555
After 5 years but within 10 years	43,430	60,451
After 10 years	86,645	111,372
Mortgage-backed securities	122,814	125,481
Fair Value	314,260	339,131
Held-to-Maturity, Amortized cost
After 10 years	4,004	4,005
Mortgage-backed securities	15	19
Total	4,019	4,024
Held-to-Maturity, Fair Value
After 10 years	3,410	3,315
Mortgage-backed securities	15	19
Fair Value	3,425	3,334
Gross realized gains on sale of investment securities available-for-sale	202
U.S. government-sponsored agencies
Investment Securities Available-for-Sale
Gross Amortized cost	51,215	71,035
Gross Unrealized Gains	3,390	3,132
Gross Unrealized Losses		(14)
Fair Value	54,605	74,153
Available-for-Sale, Fair Value
Fair Value	54,605	74,153
Mortgage-backed securities
Investment Securities Available-for-Sale
Gross Amortized cost	115,445	118,808
Gross Unrealized Gains	7,390	6,704
Gross Unrealized Losses	(21)	(31)
Fair Value	122,814	125,481
Investment Securities Held-to-Maturity
Gross Amortized cost	15	19
Fair Value	15	19
Available-for-Sale, Fair Value
Fair Value	122,814	125,481
Held-to-Maturity, Fair Value
Fair Value	15	19
Municipal securities
Investment Securities Available-for-Sale
Gross Amortized cost	127,662	130,405
Gross Unrealized Gains	6,827	6,738
Gross Unrealized Losses	(28)	(21)
Fair Value	134,461	137,122
Available-for-Sale, Fair Value
Fair Value	134,461	137,122
Pooled trust preferred and corporate securities
Investment Securities Available-for-Sale
Gross Amortized cost	2,323	2,323
Gross Unrealized Gains	57	52
Fair Value	2,380	2,375
Investment Securities Held-to-Maturity
Gross Amortized cost	4,004	4,005
Gross Unrealized Losses	(594)	(690)
Fair Value	3,410	3,315
Available-for-Sale, Fair Value
Fair Value	2,380	2,375
Held-to-Maturity, Fair Value
Fair Value	$ 3,410	$ 3,315