Investment Securities (Unrealized Gains) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	$ 410,805	$ 482,440
Investment Securities Available-for-Sale: Unrealized Gains	8,236	16,316
Investment Securities Available-for-Sale: Unrealized Losses	(5,894)	(1,941)
Investment securities: Available-for-sale	413,147	496,815
Investment Securities Held-to-Maturity: Amortized Cost	153,486	58,064
Investment Securities Held-to-Maturity: Unrealized Gains	2,150	4,372
Investment Securities Held-to-Maturity: Unrealized Losses	(3,628)	(5)
Investment Securities Held-to-Maturity: Fair Value	152,008	62,431
Total investment securities, amortized cost	564,291	540,504
Total investment securities, gross unrealized gains	10,386	20,688
Total investment securities, gross unrealized losses	(9,522)	(1,946)
Total investment securities, fair value	565,155	559,246
U.S. treasury notes [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	43,490	11,870
Investment Securities Available-for-Sale: Unrealized Gains	0	62
Investment Securities Available-for-Sale: Unrealized Losses	(1,795)	(23)
Investment securities: Available-for-sale	41,695	11,909
Federal agency obligations [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	20,939	20,207
Investment Securities Available-for-Sale: Unrealized Gains	110	333
Investment Securities Available-for-Sale: Unrealized Losses	(303)	(5)
Investment securities: Available-for-sale	20,746	20,535
Investment Securities Held-to-Maturity: Amortized Cost	10,892	4,178
Investment Securities Held-to-Maturity: Unrealized Gains	284	79
Investment Securities Held-to-Maturity: Unrealized Losses	0	0
Investment Securities Held-to-Maturity: Fair Value	11,176	4,257
Residential mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	50,070	52,400
Investment Securities Available-for-Sale: Unrealized Gains	1,022	1,385
Investment Securities Available-for-Sale: Unrealized Losses	(150)	(1)
Investment securities: Available-for-sale	50,942	53,784
Commercial mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	9,700	9,725
Investment Securities Available-for-Sale: Unrealized Gains	0	244
Investment Securities Available-for-Sale: Unrealized Losses	(182)	0
Investment securities: Available-for-sale	9,518	9,969
Investment Securities Held-to-Maturity: Amortized Cost	4,790	5,501
Investment Securities Held-to-Maturity: Unrealized Gains	11	154
Investment Securities Held-to-Maturity: Unrealized Losses	(46)	(5)
Investment Securities Held-to-Maturity: Fair Value	4,755	5,650
Obligations of U.S. states and political subdivisions [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	39,260	103,193
Investment Securities Available-for-Sale: Unrealized Gains	1,054	4,653
Investment Securities Available-for-Sale: Unrealized Losses	(37)	(132)
Investment securities: Available-for-sale	40,277	107,714
Investment Securities Held-to-Maturity: Amortized Cost	127,725	48,385
Investment Securities Held-to-Maturity: Unrealized Gains	1,727	4,139
Investment Securities Held-to-Maturity: Unrealized Losses	(3,561)	0
Investment Securities Held-to-Maturity: Fair Value	125,891	52,524
Trust preferred securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	20,635	22,279
Investment Securities Available-for-Sale: Unrealized Gains	125	144
Investment Securities Available-for-Sale: Unrealized Losses	(1,223)	(1,174)
Investment securities: Available-for-sale	19,537	21,249
Corporate bonds and notes [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	201,731	228,681
Investment Securities Available-for-Sale: Unrealized Gains	5,603	9,095
Investment Securities Available-for-Sale: Unrealized Losses	(2,099)	(371)
Investment securities: Available-for-sale	205,235	237,405
Investment Securities Held-to-Maturity: Amortized Cost	10,079
Investment Securities Held-to-Maturity: Unrealized Gains	128
Investment Securities Held-to-Maturity: Unrealized Losses	(21)
Investment Securities Held-to-Maturity: Fair Value	10,186
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost		2,120
Investment Securities Available-for-Sale: Unrealized Gains	24	0
Investment Securities Available-for-Sale: Unrealized Losses		0
Investment securities: Available-for-sale		2,120
Asset-backed securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	16,019	19,431
Investment Securities Available-for-Sale: Unrealized Gains	209	311
Investment Securities Available-for-Sale: Unrealized Losses	0	0
Investment securities: Available-for-sale	16,228	19,742
Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	2,251	2,854
Investment Securities Available-for-Sale: Unrealized Gains	45	21
Investment Securities Available-for-Sale: Unrealized Losses	(1)	(10)
Investment securities: Available-for-sale	2,295	2,865
Equity securities [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	376	535
Investment Securities Available-for-Sale: Unrealized Gains	0	0
Investment Securities Available-for-Sale: Unrealized Losses	(89)	(210)
Investment securities: Available-for-sale	287	325
Mutual funds and money market funds [Member]
Schedule of Investments [Line Items]
Investment Securities Available-for-Sale: Amortized cost	6,334	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	$ 6,387	$ 9,198