Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	$ 639,315	$ 662,144	$ 604,992
Investment securities available-for-sale, Unrealized Gains	8,448	7,168	7,131
Investment securities available-for-sale, Unrealized Losses	1,185	2,036	1,630
Available-for-sale Securities, Total	646,578	667,276	610,493
Government sponsored agencies [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	101,576	70,486	74,381
Investment securities available-for-sale, Unrealized Gains	182	240	241
Investment securities available-for-sale, Unrealized Losses	266	47	61
Available-for-sale Securities, Total	101,492	70,679	74,561
State and political subdivisions [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	49,707	42,881	43,647
Investment securities available-for-sale, Unrealized Gains	2,538	2,354	1,817
Investment securities available-for-sale, Unrealized Losses	7	0	0
Available-for-sale Securities, Total	52,238	45,235	45,464
Residential mortgage-backed securities [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	101,709	117,198	125,400
Investment securities available-for-sale, Unrealized Gains	3,543	3,883	3,910
Investment securities available-for-sale, Unrealized Losses	16	301	446
Available-for-sale Securities, Total	105,236	120,780	128,864
Collateralized Mortgage Obligations [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	297,960	332,632	295,347
Investment securities available-for-sale, Unrealized Gains	1,392	600	1,029
Investment securities available-for-sale, Unrealized Losses	274	832	444
Available-for-sale Securities, Total	299,078	332,400	295,932
Corporate bonds [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	82,219	97,558	64,828
Investment securities available-for-sale, Unrealized Gains	509	45	35
Investment securities available-for-sale, Unrealized Losses	622	835	679
Available-for-sale Securities, Total	82,106	96,768	64,184
Preferred stock [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	6,144	1,389	1,389
Investment securities available-for-sale, Unrealized Gains	284	46	99
Investment securities available-for-sale, Unrealized Losses	0	21	0
Available-for-sale Securities, Total	$ 6,428	$ 1,414	$ 1,488

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15E

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details