Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income (expense)		$ 28,679	$ 27,735
Provision for loan losses		400	500
Net interest income after provision for loan losses		28,279	27,235
Noninterest income		14,510	14,634
Depreciation and amortization expense		1,178	1,211
Other noninterest expenses related to segments		24,108	24,239
Total noninterest expense		25,286	25,450
Income before income taxes		17,503	16,419
Income tax expense		5,721	5,484
Net income		11,782	10,935
Total assets		4,388,763	3,838,210	$ 4,381,115
Expenditures for long-lived assets		733	1,177
Change in fair value of contingent consideration		(310)	25
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		23,557	22,607
Provision for loan losses		400	500
Net interest income after provision for loan losses		23,157	22,107
Noninterest income		4,442	4,940
Depreciation and amortization expense		663	687
Other noninterest expenses related to segments		14,607	13,991
Total noninterest expense		15,270	14,678
Income before income taxes		12,329	12,369
Income tax expense		4,029	4,255
Net income		8,300	8,114
Total assets		3,344,773	3,178,248
Expenditures for long-lived assets		373	1,019
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		(32)	(18)
Provision for loan losses		0	0
Net interest income after provision for loan losses		(32)	(18)
Noninterest income		9,477	9,174
Depreciation and amortization expense		463	469
Other noninterest expenses related to segments	[1]	6,448	6,799
Total noninterest expense		6,911	7,268
Income before income taxes		2,534	1,888
Income tax expense		978	733
Net income		1,556	1,155
Total assets		64,984	64,496
Expenditures for long-lived assets		302	84
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		5,154	5,146
Provision for loan losses		0	0
Net interest income after provision for loan losses		5,154	5,146
Noninterest income		591	520
Depreciation and amortization expense		52	55
Other noninterest expenses related to segments		3,053	3,449
Total noninterest expense		3,105	3,504
Income before income taxes		2,640	2,162
Income tax expense		714	496
Net income		1,926	1,666
Total assets		979,006	595,466
Expenditures for long-lived assets		$ 58	$ 74

[1] Other noninterest expenses for the Wealth Management Services segment includes a $310 thousand benefit resulting from the reduction of a contingent consideration liability in the three months ended March 31, 2017.