Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012 segment	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting [Abstract]
Number of Primary Operating Segments									2
Segment Reporting Information [Line Items]
Goodwill	$ 30,334				$ 30,334				$ 30,334	$ 30,334	$ 2,064
Intangibles, net	7,406				9,285				7,406	9,285
Deposits	2,658,851				2,791,353				2,658,851	2,791,353
Total assets	3,325,786				3,377,779				3,325,786	3,377,779	2,800,199
Income Statement Information
Net interest income (expense)	40,051	37,484	34,133	30,629	32,204	26,769	31,004	22,708	142,297	112,685	83,983
Provision for loan losses									22,790	16,103	33,735
Noninterest Income	(3,576)	7,832	845	3,983	601	8,726	4,218	4,963	9,084	18,508	18,360
Noninterest Expense	22,617	21,282	21,414	21,364	23,427	18,302	18,024	17,965	86,677	77,718	62,212
Income before income tax expense	7,289	12,097	13,283	9,245	9,522	9,121	12,623	6,106	41,914	37,372	6,396
Banking
Segment Reporting Information [Line Items]
Total assets	3,195,096				3,278,328				3,195,096	3,278,328	2,683,937
Income Statement Information
Net interest income (expense)									146,726	118,063	89,972
Provision for loan losses									22,790	16,103	33,735
Noninterest Income									(834)	7,526	9,528
Noninterest Expense									73,500	66,548	50,877
Income before income tax expense									49,602	42,938	14,888
Wealth Management
Segment Reporting Information [Line Items]
Total assets	112,020				90,068				112,020	90,068	102,122
Income Statement Information
Net interest income (expense)									(652)	(1,245)	(1,430)
Provision for loan losses									0	0	0
Noninterest Income									9,506	10,486	8,664
Noninterest Expense									7,716	7,236	7,516
Income before income tax expense									1,138	2,005	(282)
Corporate and Intercompany
Segment Reporting Information [Line Items]
Total assets	18,670				9,383				18,670	9,383	14,140
Income Statement Information
Net interest income (expense)									(3,777)	(4,133)	(4,559)
Provision for loan losses									0	0	0
Noninterest Income									412	496	168
Noninterest Expense									5,461	3,934	3,819
Income before income tax expense									$ (8,826)	$ (7,571)	$ (8,210)