Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	$ 303,860	$ 320,556
Available for sale Securities, Gross Unrealized Gains	8,512	14,020
Available for sale Securities, Unrealized Losses Other	(6,236)	(2,638)
Available for sale Securities, Other Than Temporary Impairment	(2,281)	(2,652)
Available for sale Securities, Fair Value, Total	303,855	329,286
Held to maturity Securities, Amortized Cost	225,278	178,318
Held to maturity Securities, Gross Unrealized Gains	3,939	7,508
Held to maturity Securities, Unrealized Losses Other	(3,366)	(2)
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	225,851	185,824
Amortized Cost	529,138	498,874
Gross Unrealized Gains	12,451	21,528
Unrealized Losses Other	(9,602)	(2,640)
Other Than Temporary Impairment	(2,281)	(2,652)
Fair Value	529,706	515,110
U. S. Government Agency Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	20,050	20,053
Available for sale Securities, Gross Unrealized Gains		769
Available for sale Securities, Unrealized Losses Other	(457)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	19,593	20,822
U.S. Treasury Securities [Member]
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	1,012	1,013
Held to maturity Securities, Gross Unrealized Gains	62	121
Held to maturity Securities, Unrealized Losses Other
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	1,074	1,134
Agency Mortgage-Backed Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	193,741	209,381
Available for sale Securities, Gross Unrealized Gains	7,425	12,158
Available for sale Securities, Unrealized Losses Other	(2,865)	(114)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	198,301	221,425
Held to maturity Securities, Amortized Cost	56,889	72,360
Held to maturity Securities, Gross Unrealized Gains	1,980	4,233
Held to maturity Securities, Unrealized Losses Other
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	58,869	76,593
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	66,087	67,412
Available for sale Securities, Gross Unrealized Gains	612	1,001
Available for sale Securities, Unrealized Losses Other	(603)	(37)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	66,096	68,376
Held to maturity Securities, Amortized Cost	159,945	97,507
Held to maturity Securities, Gross Unrealized Gains	1,632	2,875
Held to maturity Securities, Unrealized Losses Other	(3,366)	(2)
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	158,211	100,380
State, County, and Municipal Securities [Member]
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	916	915
Held to maturity Securities, Gross Unrealized Gains	10	11
Held to maturity Securities, Unrealized Losses Other
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	926	926
Private Mortgage-Backed Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,820	3,227
Available for sale Securities, Gross Unrealized Gains
Available for sale Securities, Unrealized Losses Other
Available for sale Securities, Other Than Temporary Impairment	216	305
Available for sale Securities, Fair Value, Total	3,036	3,532
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,233	2,255
Available for sale Securities, Gross Unrealized Gains	11
Available for sale Securities, Unrealized Losses Other		(15)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	2,244	2,240
Held to maturity Securities, Amortized Cost	1,510	1,516
Held to maturity Securities, Gross Unrealized Gains	20	10
Held to maturity Securities, Unrealized Losses Other
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	1,530	1,526
Pooled Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	8,158	8,353
Available for sale Securities, Gross Unrealized Gains
Available for sale Securities, Unrealized Losses Other	(2,044)	(2,415)
Available for sale Securities, Other Than Temporary Impairment	(2,497)	(2,957)
Available for sale Securities, Fair Value, Total	3,617	2,981
Marketable Equity Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	10,771	9,875
Available for sale Securities, Gross Unrealized Gains	464	92
Available for sale Securities, Unrealized Losses Other	(267)	(57)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	10,968	9,910
Corporate Debt Securities [Member]
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	5,006	5,007
Held to maturity Securities, Gross Unrealized Gains	235	258
Held to maturity Securities, Unrealized Losses Other
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	$ 5,241	$ 5,265

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