Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Segment	Mar. 31, 2013
Segment Reporting Information [Line Items]
Number of segments in which the business operates	3
Net interest income	$ 94,904	$ 88,975
Provision for loan losses, net	(742)	(2,838)
Noninterest income	44,078	44,339
Noninterest expense	101,618	102,145
Income before income taxes	38,106	34,007
Income taxes	9,103	9,141
Net Income	29,003	24,866
Selected Financial Information [Abstract]
Average assets	11,918,816	10,799,967
Depreciation and amortization	8,756	8,380
General Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	93,839	87,812
Provision for loan losses, net	(740)	(2,836)
Noninterest income	27,839	30,189
Noninterest expense	88,084	90,306
Income before income taxes	34,334	30,531
Income taxes	7,785	7,933
Net Income	26,549	22,598
Selected Financial Information [Abstract]
Average assets	11,780,274	10,658,486
Depreciation and amortization	8,478	8,079
Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest income	995	1,098
Provision for loan losses, net	(2)	(2)
Noninterest income	8,141	6,906
Noninterest expense	6,937	5,830
Income before income taxes	2,201	2,176
Income taxes	729	723
Net Income	1,472	1,453
Selected Financial Information [Abstract]
Average assets	73,100	76,227
Depreciation and amortization	48	42
Insurance [Member]
Segment Reporting Information [Line Items]
Net interest income	70	65
Noninterest income	8,098	7,244
Noninterest expense	6,597	6,009
Income before income taxes	1,571	1,300
Income taxes	589	485
Net Income	982	815
Selected Financial Information [Abstract]
Average assets	65,442	65,254
Depreciation and amortization	$ 230	$ 259