Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 27,735	$ 25,702
Provision for loan losses	500	0
Net interest income after provision for loan losses	27,235	25,702
Noninterest income	14,634	14,020
Depreciation and amortization expense	1,211	1,037
Other noninterest expenses related to segments	24,239	22,494
Total noninterest expense	25,450	23,531
Income before income taxes	16,419	16,191
Income tax expense	5,484	5,181
Net income	10,935	11,010
Total assets	3,838,210	3,602,514	$ 3,771,604
Expenditures for long-lived assets	1,177	1,226
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	22,607	20,625
Provision for loan losses	500	0
Net interest income after provision for loan losses	22,107	20,625
Noninterest income	4,940	5,078
Depreciation and amortization expense	687	671
Other noninterest expenses related to segments	13,991	13,587
Total noninterest expense	14,678	14,258
Income before income taxes	12,369	11,445
Income tax expense	4,255	3,730
Net income	8,114	7,715
Total assets	3,178,248	3,015,691
Expenditures for long-lived assets	1,019	1,067
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(18)	(14)
Provision for loan losses	0	0
Net interest income after provision for loan losses	(18)	(14)
Noninterest income	9,174	8,435
Depreciation and amortization expense	469	306
Other noninterest expenses related to segments	6,799	5,915
Total noninterest expense	7,268	6,221
Income before income taxes	1,888	2,200
Income tax expense	733	844
Net income	1,155	1,356
Total assets	64,496	52,568
Expenditures for long-lived assets	84	114
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	5,146	5,091
Provision for loan losses	0	0
Net interest income after provision for loan losses	5,146	5,091
Noninterest income	520	507
Depreciation and amortization expense	55	60
Other noninterest expenses related to segments	3,449	2,992
Total noninterest expense	3,504	3,052
Income before income taxes	2,162	2,546
Income tax expense	496	607
Net income	1,666	1,939
Total assets	595,466	534,255
Expenditures for long-lived assets	$ 74	$ 45