Investment Securities (Summary of Amortized Cost and Fair Value of Available-for-Sale Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	$ 580,234	$ 662,144
Investment securities available-for-sale, Unrealized Gains	7,518	7,168
Investment securities available-for-sale, Unrealized Losses	943	2,036
Available-for-sale Securities, Total Fair Value	586,809	667,276
Government sponsored agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	97,529	70,486
Investment securities available-for-sale, Unrealized Gains	241	240
Investment securities available-for-sale, Unrealized Losses	213	47
Available-for-sale Securities, Total Fair Value	97,557	70,679
State and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	47,663	42,881
Investment securities available-for-sale, Unrealized Gains	2,302	2,354
Investment securities available-for-sale, Unrealized Losses	0	0
Available-for-sale Securities, Total Fair Value	49,965	45,235
Residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	96,320	117,198
Investment securities available-for-sale, Unrealized Gains	3,100	3,883
Investment securities available-for-sale, Unrealized Losses	9	301
Available-for-sale Securities, Total Fair Value	99,411	120,780
Collateralized mortgage obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	262,790	332,632
Investment securities available-for-sale, Unrealized Gains	984	600
Investment securities available-for-sale, Unrealized Losses	182	832
Available-for-sale Securities, Total Fair Value	263,592	332,400
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	69,788	97,558
Investment securities available-for-sale, Unrealized Gains	546	45
Investment securities available-for-sale, Unrealized Losses	539	835
Available-for-sale Securities, Total Fair Value	69,795	96,768
Preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale, Amortized Cost	6,144	1,389
Investment securities available-for-sale, Unrealized Gains	345	46
Investment securities available-for-sale, Unrealized Losses	0	21
Available-for-sale Securities, Total Fair Value	$ 6,489	$ 1,414

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

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

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

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

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

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

-Publisher FASB

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

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

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+ 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