Investment Securities (Summary of Amortized Cost and Fair Value of Available-For-Sale Investment Securities) (Details) (USD $)	3 Months Ended
Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
preferred stock investment security carried on a cost basis	$ 4,800,000
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	735,443,000	580,234,000	674,370,000
Investment securities available-for-sale, Unrealized Gains	4,463,000	7,518,000	7,703,000
Investment securities available-for-sale, Unrealized Losses	5,854,000	943,000	1,842,000
Available-for-sale Securities, Total	734,052,000	586,809,000	680,231,000
gain on sale of preferred stock investment security	200,000
Government sponsored agencies [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	92,239,000	97,529,000	95,021,000
Investment securities available-for-sale, Unrealized Gains	249,000	241,000	205,000
Investment securities available-for-sale, Unrealized Losses	400,000	213,000	81,000
Available-for-sale Securities, Total	92,088,000	97,557,000	95,145,000
State and political subdivisions [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	44,288,000	47,663,000	49,799,000
Investment securities available-for-sale, Unrealized Gains	1,500,000	2,302,000	2,397,000
Investment securities available-for-sale, Unrealized Losses	8,000	0	65,000
Available-for-sale Securities, Total	45,780,000	49,965,000	52,131,000
Residential mortgage-backed securities [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	311,425,000	96,320,000	109,730,000
Investment securities available-for-sale, Unrealized Gains	1,166,000	3,100,000	3,561,000
Investment securities available-for-sale, Unrealized Losses	4,219,000	9,000	200,000
Available-for-sale Securities, Total	308,372,000	99,411,000	113,091,000
Collateralized Mortgage Obligations [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	221,025,000	262,790,000	321,178,000
Investment securities available-for-sale, Unrealized Gains	463,000	984,000	1,321,000
Investment securities available-for-sale, Unrealized Losses	973,000	182,000	602,000
Available-for-sale Securities, Total	220,515,000	263,592,000	321,897,000
Corporate bonds [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	65,077,000	69,788,000	92,498,000
Investment securities available-for-sale, Unrealized Gains	692,000	546,000	162,000
Investment securities available-for-sale, Unrealized Losses	254,000	539,000	894,000
Available-for-sale Securities, Total	65,515,000	69,795,000	91,766,000
Preferred stock [Member]
Available-for-sale Securities
Investment securities available-for-sale, Amortized Cost	1,389,000	6,144,000	6,144,000
Investment securities available-for-sale, Unrealized Gains	393,000	345,000	57,000
Investment securities available-for-sale, Unrealized Losses	0	0	0
Available-for-sale Securities, Total	$ 1,782,000	$ 6,489,000	$ 6,201,000

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 Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

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

Reference 2: 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 3: 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 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 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 6: 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 7: 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.

Reference 8: 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 9: 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 10: 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.

+ 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