Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Available-for-sale: [Abstract]
Amortized Cost	$ 544,568		$ 500,862
Gross Unrealized Gains	4,541		11,871
Gross Unrealized (Losses)	(15,274)		(4,424)
Fair Value	533,835		508,309
Realized Investment Gains (Losses) [Abstract]
Gross gains	835	823
Gross losses	0	0
U.S. Treasury securities and obligations of U.S. government corporations & agencies
Available-for-sale: [Abstract]
Amortized Cost	213,347		180,851
Gross Unrealized Gains	229		1,321
Gross Unrealized (Losses)	(6,059)		(3)
Fair Value	207,517		182,169
Obligations of states and political subdivisions
Available-for-sale: [Abstract]
Amortized Cost	59,933		53,064
Gross Unrealized Gains	1,157		3,163
Gross Unrealized (Losses)	(1,697)		(20)
Fair Value	59,393		56,207
Mortgage-backed securities: GSE residential
Available-for-sale: [Abstract]
Amortized Cost	260,463		252,310
Gross Unrealized Gains	3,129		7,162
Gross Unrealized (Losses)	(3,545)		(12)
Fair Value	260,047		259,460
Trust preferred securities
Available-for-sale: [Abstract]
Amortized Cost	4,790		4,974
Gross Unrealized Gains	0		0
Gross Unrealized (Losses)	(3,955)		(4,389)
Fair Value	835		585
Number of trust preferred securities	3
Trust preferred securities \| Minimum [Member]
Available-for-sale: [Abstract]
Maturities of Debt Securities	seventeen years
Trust preferred securities \| Maximum [Member]
Available-for-sale: [Abstract]
Maturities of Debt Securities	twenty-four years
Other securities
Available-for-sale: [Abstract]
Amortized Cost	6,035		9,663
Gross Unrealized Gains	26		225
Gross Unrealized (Losses)	(18)		0
Fair Value	$ 6,043		$ 9,888

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

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Represents the number of trust preferred securities held by the entity during the period.

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No definition available.

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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

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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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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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

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No definition available.

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