Securities (Summary of Investments) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	$ 368,768	$ 387,910
Available for sale securities unrealized gains	11,107	11,520
Available for sale securities unrealized losses	(3,802)	(6,527)
Available for sale, at fair value	376,073	392,903
Held to maturity securities	26,480	29,905
Held to maturity securities unrealized gains	594	14
Held to maturity securities unrealized losses	0	(54)
Held to maturity securities fair value	27,074	29,865
Total available for sale and held to maturity securities amortized cost	395,248	417,815
Total available for sale and held to maturity securities unrealized gains	11,701	11,534
Total available for sale and held to maturity securities unrealized losses	(3,802)	(6,581)
Total available for sale and held to maturity securities fair value	403,147	422,768
Obligations of U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	31,008	54,474
Available for sale securities unrealized gains	0	720
Available for sale securities unrealized losses	(89)	(79)
Available for sale, at fair value	30,919	55,115
Mortgage-backed securities issued by US Government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	248,369	230,387
Available for sale securities unrealized gains	9,012	8,369
Available for sale securities unrealized losses	(160)	(401)
Available for sale, at fair value	257,221	238,355
Held to maturity securities	26,480	29,905
Held to maturity securities unrealized gains	594	14
Held to maturity securities unrealized losses	0	(54)
Held to maturity securities fair value	27,074	29,865
Obligations of states and political subdivisions [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	52,526	60,659
Available for sale securities unrealized gains	1,991	2,200
Available for sale securities unrealized losses	0	0
Available for sale, at fair value	54,517	62,859
Trust preferred securities: Individual name issuers [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	30,743	30,715
Available for sale securities unrealized gains	0	0
Available for sale securities unrealized losses	(3,546)	(6,031)
Available for sale, at fair value	27,197	24,684
Trust preferred securities: Collateralized debt obligations [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis		547
Available for sale securities unrealized gains		0
Available for sale securities unrealized losses		0
Available for sale, at fair value		547
Corporate bonds [Member]
Schedule of Available for Sale and Held to Maturty Securities [Line Items]
Available for sale securities amortized cost basis	6,122	11,128
Available for sale securities unrealized gains	104	231
Available for sale securities unrealized losses	(7)	(16)
Available for sale, at fair value	$ 6,219	$ 11,343

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

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