Securities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	$ 284,585	$ 320,556
Available for Sale Securities Gross Gain unrealized	8,139	14,020
Available for sale Securities, Unrealized Losses Other	(6,348)	(2,638)
Available for sale Securities, Other Than Temporary Impairment	(1,978)	(2,652)
Available for sale Securities, Fair Value, Total	284,398	329,286
Held to maturity Securities, Amortized Cost	317,373	178,318
Held to Maturity Securities Holding Gain Unrecognized	4,376	7,508
Held to Maturity Securities Holding Loss Unrecognized	(5,152)	(2)
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	316,597	185,824
Amortized Cost	601,958	498,874
Gross Unrealized Gains	12,515	21,528
Unrealized Losses Other	(11,500)	(2,640)
Other Than Temporary Impairment	(1,978)	(2,652)
Fair Value	600,995	515,110
U. S. Government Agency Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	20,048	20,053
Available for Sale Securities Gross Gain unrealized		769
Available for sale Securities, Unrealized Losses Other	(449)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	19,599	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 Holding Gain Unrecognized	57	121
Held to Maturity Securities Holding Loss Unrecognized	0
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	1,069	1,134
Agency Mortgage-Backed Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	179,366	209,381
Available for Sale Securities Gross Gain unrealized	6,996	12,158
Available for sale Securities, Unrealized Losses Other	(3,001)	(114)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	183,361	221,425
Held to maturity Securities, Amortized Cost	115,983	72,360
Held to Maturity Securities Holding Gain Unrecognized	2,961	4,233
Held to Maturity Securities Holding Loss Unrecognized	(114)
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	118,830	76,593
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	61,481	67,412
Available for Sale Securities Gross Gain unrealized	472	1,001
Available for sale Securities, Unrealized Losses Other	(698)	(37)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	61,255	68,376
Held to maturity Securities, Amortized Cost	193,190	97,507
Held to Maturity Securities Holding Gain Unrecognized	1,104	2,875
Held to Maturity Securities Holding Loss Unrecognized	(5,038)	(2)
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	189,256	100,380
State, County, and Municipal Securities [Member]
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	676	915
Held to Maturity Securities Holding Gain Unrecognized	11	11
Held to Maturity Securities Holding Loss Unrecognized	0
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	687	926
Private Mortgage-Backed Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,599	3,227
Available for Sale Securities Gross Gain unrealized
Available for sale Securities, Unrealized Losses Other
Available for sale Securities, Other Than Temporary Impairment	264	305
Available for sale Securities, Fair Value, Total	2,863	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	2,222	2,255
Available for Sale Securities Gross Gain unrealized
Available for sale Securities, Unrealized Losses Other	(49)	(15)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	2,173	2,240
Held to maturity Securities, Amortized Cost	1,507	1,516
Held to Maturity Securities Holding Gain Unrecognized	22	10
Held to Maturity Securities Holding Loss Unrecognized	0
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	1,529	1,526
Pooled Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	8,113	8,353
Available for Sale Securities Gross Gain unrealized
Available for sale Securities, Unrealized Losses Other	(1,900)	(2,415)
Available for sale Securities, Other Than Temporary Impairment	(2,242)	(2,957)
Available for sale Securities, Fair Value, Total	3,971	2,981
Marketable Equity Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	10,756	9,875
Available for Sale Securities Gross Gain unrealized	671	92
Available for sale Securities, Unrealized Losses Other	(251)	(57)
Available for sale Securities, Other Than Temporary Impairment
Available for sale Securities, Fair Value, Total	11,176	9,910
Corporate Debt Securities [Member]
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	5,005	5,007
Held to Maturity Securities Holding Gain Unrecognized	221	258
Held to Maturity Securities Holding Loss Unrecognized	0
Held to maturity Securities, Other Than Temporary Impairment
Held to Maturity, Fair Value, Total	$ 5,226	$ 5,265