Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Available-for-sale: [Abstract]
Amortized Cost-AFS	$ 516,916		$ 473,756
Gross Unrealized Gains	13,442		10,608
Gross Unrealized Losses	(4,606)		(5,448)
Total available-for-sale securities	525,752		478,916
Held-to-maturity Securities [Abstract]
Fair Value	0		51
Realized Investment Gains (Losses) [Abstract]
Gross gains	933	412
Gross losses	0	0
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member]
Available-for-sale: [Abstract]
Amortized Cost-AFS	174,089		164,812
Gross Unrealized Gains	1,414		1,294
Gross Unrealized Losses	(28)		(40)
Total available-for-sale securities	175,475		166,066
Obligations of States and Political Subdivisions [Member]
Available-for-sale: [Abstract]
Amortized Cost-AFS	51,327		38,828
Gross Unrealized Gains	3,305		2,374
Gross Unrealized Losses	(21)		0
Total available-for-sale securities	54,611		41,202
Held-to-maturity Securities [Abstract]
Amortized Cost			51
Held-to-maturity Securities, Unrecognized Holding Gain			0
Fair Value			51
Mortgage-backed Securities: GSE Residential [Member]
Available-for-sale: [Abstract]
Amortized Cost-AFS	276,889		254,930
Gross Unrealized Gains	8,552		6,940
Gross Unrealized Losses	(29)		(37)
Total available-for-sale securities	285,412		261,833
Trust Preferred Securities [Member]
Available-for-sale: [Abstract]
Amortized Cost-AFS	4,974		5,625
Gross Unrealized Gains	0		0
Gross Unrealized Losses	(4,524)		(4,906)
Total available-for-sale securities	450		719
Held-to-maturity Securities [Abstract]
Number of trust preferred securities	3
Trust Preferred Securities [Member] \| Minimum [Member]
Held-to-maturity Securities [Abstract]
Maturities of Debt Securities	eighteen years
Trust Preferred Securities [Member] \| Maximum [Member]
Held-to-maturity Securities [Abstract]
Maturities of Debt Securities	twenty-six years
Other Securities [Member]
Available-for-sale: [Abstract]
Amortized Cost-AFS	9,637		9,561
Gross Unrealized Gains	171		0
Gross Unrealized Losses	(4)		(465)
Total available-for-sale securities	$ 9,804		$ 9,096

Represents the range of maturities of debt securities held by the entity during the period.

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Total of debt securities categorized neither as held-to-maturity nor trading which are intended be sold or mature within one year from the balance sheet date or the normal operating cycle, whichever is longer.

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For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity. The held-to-maturity category is for those securities that the entity has the positive intent and ability to hold until maturity.

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Amount of investments in debt securities categorized as held-to-maturity valued at amortized cost, excludes other than temporary impairment (OTTI).

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