Investment Securities (Unrealized Gains) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	$ 482,440	$ 417,939
Investment Securities Available-for-Sale: Unrealized Gains	16,316	6,714
Investment Securities Available-for-Sale: Unrealized Losses	(1,941)	(10,146)
Investment Securities Available-for-Sale: Fair Value	496,815	414,507
Investment Securities Held-to-Maturity: Amortized Cost	58,064	72,233
Investment Securities Held-to-Maturity: Unrealized Gains	4,372	2,792
Investment Securities Held-to-Maturity: Unrealized Losses	(5)	(103)
Investment Securities Held-to-Maturity: Fair Value	62,431	74,922
Total investment securities, amortized cost	540,504	490,172
Total investment securities, gross unrealized gains	20,688	9,506
Total investment securities, gross unrealized losses	(1,946)	(10,249)
Total investment securities, fair value	559,246	489,429
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	20,207	24,781
Investment Securities Available-for-Sale: Unrealized Gains	333	188
Investment Securities Available-for-Sale: Unrealized Losses	(5)
Investment Securities Available-for-Sale: Fair Value	20,535	24,969
Investment Securities Held-to-Maturity: Amortized Cost	4,178	28,262
Investment Securities Held-to-Maturity: Unrealized Gains	79	177
Investment Securities Held-to-Maturity: Unrealized Losses		(34)
Investment Securities Held-to-Maturity: Fair Value	4,257	28,405
Residential mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	52,400	113,213
Investment Securities Available-for-Sale: Unrealized Gains	1,385	2,157
Investment Securities Available-for-Sale: Unrealized Losses	(1)	(6)
Investment Securities Available-for-Sale: Fair Value	53,784	115,364
Commercial mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	9,725
Investment Securities Available-for-Sale: Unrealized Gains	244
Investment Securities Available-for-Sale: Fair Value	9,969
Investment Securities Held-to-Maturity: Amortized Cost	5,501	6,276
Investment Securities Held-to-Maturity: Unrealized Gains	154
Investment Securities Held-to-Maturity: Unrealized Losses	(5)	(69)
Investment Securities Held-to-Maturity: Fair Value	5,650	6,207
Obligations of U.S. states and political subdivisions [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	103,193	66,309
Investment Securities Available-for-Sale: Unrealized Gains	4,653	2,900
Investment Securities Available-for-Sale: Unrealized Losses	(132)	(36)
Investment Securities Available-for-Sale: Fair Value	107,714	69,173
Investment Securities Held-to-Maturity: Amortized Cost	48,385	37,695
Investment Securities Held-to-Maturity: Unrealized Gains	4,139	2,615
Investment Securities Held-to-Maturity: Fair Value	52,524	40,310
Trust preferred securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	22,279	20,567
Investment Securities Available-for-Sale: Unrealized Gains	144	14
Investment Securities Available-for-Sale: Unrealized Losses	(1,174)	(4,394)
Investment Securities Available-for-Sale: Fair Value	21,249	16,187
Corporate bonds and notes [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	228,681	175,812
Investment Securities Available-for-Sale: Unrealized Gains	9,095	1,382
Investment Securities Available-for-Sale: Unrealized Losses	(371)	(4,077)
Investment Securities Available-for-Sale: Fair Value	237,405	173,117
Asset-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	19,431	7,614
Investment Securities Available-for-Sale: Unrealized Gains	311	52
Investment Securities Available-for-Sale: Unrealized Losses		(13)
Investment Securities Available-for-Sale: Fair Value	19,742	7,653
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	2,120	3,226
Investment Securities Available-for-Sale: Unrealized Losses		(1,327)
Investment Securities Available-for-Sale: Fair Value	2,120	1,899
Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	2,854
Investment Securities Available-for-Sale: Unrealized Gains	21
Investment Securities Available-for-Sale: Unrealized Losses	(10)
Investment Securities Available-for-Sale: Fair Value	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	(210)	(273)
Investment Securities Available-for-Sale: Fair Value	325	262
Other securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	9,145	5,882
Investment Securities Available-for-Sale: Unrealized Gains	68	21
Investment Securities Available-for-Sale: Unrealized Losses	(15)	(20)
Investment Securities Available-for-Sale: Fair Value	$ 9,198	$ 5,883

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

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