Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015		Jun. 30, 2016	Jun. 30, 2015		Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 26,776	$ 26,028		$ 54,511	$ 51,730
Provision for loan losses	450	100		950	100
Net interest income after provision for loan losses	26,326	25,928		53,561	51,630
Noninterest income	15,914	15,261		30,548	29,281
Depreciation and amortization expense	1,224	988		2,435	2,026
Other noninterest expenses related to segments	24,806	23,311		49,045	45,804
Total noninterest expense	26,030	24,299		51,480	47,830
Income before income taxes	16,210	16,890		32,629	33,081
Income tax expense	5,153	5,387		10,637	10,568
Net income	11,057	11,503		21,992	22,513
Total assets	3,917,081	3,644,477		3,917,081	3,644,477		$ 3,771,604
Expenditures for long-lived assets	639	1,118		1,816	2,344
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	21,947	21,212		44,554	41,837
Provision for loan losses	450	100		950	100
Net interest income after provision for loan losses	21,497	21,112		43,604	41,737
Noninterest income	5,290	5,588		10,230	10,666
Depreciation and amortization expense	697	638		1,384	1,310
Other noninterest expenses related to segments	15,038	13,868		29,029	27,454
Total noninterest expense	15,735	14,506		30,413	28,764
Income before income taxes	11,052	12,194		23,421	23,639
Income tax expense	3,767	3,993		8,022	7,723
Net income	7,285	8,201		15,399	15,916
Total assets	3,238,789	3,058,410		3,238,789	3,058,410
Expenditures for long-lived assets	306	943		1,325	2,010
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(17)	(9)		(35)	(23)
Provision for loan losses	0	0		0	0
Net interest income after provision for loan losses	(17)	(9)		(35)	(23)
Noninterest income	9,481	8,912		18,655	17,347
Depreciation and amortization expense	470	299		939	605
Other noninterest expenses related to segments	6,701	6,465	[1]	13,500	12,380	[2]
Total noninterest expense	7,171	6,764		14,439	12,985
Income before income taxes	2,293	2,139		4,181	4,339
Income tax expense	871	838		1,604	1,682
Net income	1,422	1,301		2,577	2,657
Total assets	65,423	53,236		65,423	53,236
Expenditures for long-lived assets	104	87		188	201
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	4,846	4,825		9,992	9,916
Provision for loan losses	0	0		0	0
Net interest income after provision for loan losses	4,846	4,825		9,992	9,916
Noninterest income	1,143	761		1,663	1,268
Depreciation and amortization expense	57	51		112	111
Other noninterest expenses related to segments	3,067	2,978		6,516	5,970
Total noninterest expense	3,124	3,029		6,628	6,081
Income before income taxes	2,865	2,557		5,027	5,103
Income tax expense	515	556		1,011	1,163
Net income	2,350	2,001		4,016	3,940
Total assets	612,869	532,831		612,869	532,831
Expenditures for long-lived assets	$ 229	$ 88		$ 303	$ 133

[1] Other noninterest expenses for the Wealth Management Services segment includes $433 thousand of acquisition related expenses for the three months ended June 30, 2015.

[2] Other noninterest expenses for the Wealth Management Services segment includes $433 thousand of acquisition related expenses for the six months ended June 30, 2015.