Investment Securities (Unrealized Gains) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	$ 443,400	$ 482,440
Investment Securities Available-for-Sale: Unrealized Gains	16,584	16,316
Investment Securities Available-for-Sale: Unrealized Losses	(1,980)	(1,941)
Investment Securities Available-for-Sale: Fair Value	458,004	496,815
Investment Securities Held-to-Maturity: Amortized Cost	78,212	58,064
Investment Securities Held-to-Maturity: Unrealized Gains	3,984	4,372
Investment Securities Held-to-Maturity: Unrealized Losses	(275)	(5)
Investment Securities Held-to-Maturity: Fair Value	81,921	62,431
Total investment securities, amortized cost	521,612	540,504
Total investment securities, gross unrealized gains	20,568	20,688
Total investment securities, gross unrealized losses	(2,255)	(1,946)
Total investment securities, fair value	539,925	559,246
U.S. treasury notes [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost		11,870
Investment Securities Available-for-Sale: Unrealized Gains		62
Investment Securities Available-for-Sale: Unrealized Losses		(23)
Investment Securities Available-for-Sale: Fair Value		11,909
Federal agency obligations [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	16,146	20,207
Investment Securities Available-for-Sale: Unrealized Gains	144	333
Investment Securities Available-for-Sale: Unrealized Losses	(121)	(5)
Investment Securities Available-for-Sale: Fair Value	16,169	20,535
Investment Securities Held-to-Maturity: Amortized Cost	3,893	4,178
Investment Securities Held-to-Maturity: Unrealized Gains	157	79
Investment Securities Held-to-Maturity: Fair Value	4,050	4,257
Residential mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	50,180	52,400
Investment Securities Available-for-Sale: Unrealized Gains	1,334	1,385
Investment Securities Available-for-Sale: Unrealized Losses		(1)
Investment Securities Available-for-Sale: Fair Value	51,514	53,784
Commercial mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	9,717	9,725
Investment Securities Available-for-Sale: Unrealized Gains	209	244
Investment Securities Available-for-Sale: Fair Value	9,926	9,969
Investment Securities Held-to-Maturity: Amortized Cost	5,125	5,501
Investment Securities Held-to-Maturity: Unrealized Gains	141	154
Investment Securities Held-to-Maturity: Unrealized Losses	(6)	(5)
Investment Securities Held-to-Maturity: Fair Value	5,260	5,650
Obligations of U.S. states and political subdivisions [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	92,384	103,193
Investment Securities Available-for-Sale: Unrealized Gains	3,865	4,653
Investment Securities Available-for-Sale: Unrealized Losses	(291)	(132)
Investment Securities Available-for-Sale: Fair Value	95,958	107,714
Investment Securities Held-to-Maturity: Amortized Cost	69,194	48,385
Investment Securities Held-to-Maturity: Unrealized Gains	3,686	4,139
Investment Securities Held-to-Maturity: Unrealized Losses	(269)
Investment Securities Held-to-Maturity: Fair Value	72,611	52,524
Trust preferred securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	21,427	22,279
Investment Securities Available-for-Sale: Unrealized Gains	489	144
Investment Securities Available-for-Sale: Unrealized Losses	(1,128)	(1,174)
Investment Securities Available-for-Sale: Fair Value	20,788	21,249
Corporate bonds and notes [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	227,011	228,681
Investment Securities Available-for-Sale: Unrealized Gains	10,077	9,095
Investment Securities Available-for-Sale: Unrealized Losses	(257)	(371)
Investment Securities Available-for-Sale: Fair Value	236,831	237,405
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost		2,120
Investment Securities Available-for-Sale: Fair Value		2,120
Asset-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	19,236	19,431
Investment Securities Available-for-Sale: Unrealized Gains	359	311
Investment Securities Available-for-Sale: Fair Value	19,595	19,742
Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	2,853	2,854
Investment Securities Available-for-Sale: Unrealized Gains	39	21
Investment Securities Available-for-Sale: Unrealized Losses	(3)	(10)
Investment Securities Available-for-Sale: Fair Value	2,889	2,865
Equity securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	535	535
Investment Securities Available-for-Sale: Unrealized Losses	(165)	(210)
Investment Securities Available-for-Sale: Fair Value	370	325
Other securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	3,911	9,145
Investment Securities Available-for-Sale: Unrealized Gains	68	68
Investment Securities Available-for-Sale: Unrealized Losses	(15)	(15)
Investment Securities Available-for-Sale: Fair Value	$ 3,964	$ 9,198

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

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