Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net interest income (expense)	[1]	$ 30,945	$ 33,858	$ 63,547	$ 68,442
Provision for credit losses		2,200	525	9,236	1,175
Net interest income after provision for credit losses		28,745	33,333	54,311	67,267
Noninterest income	[1]	26,320	16,753	46,247	32,120
Depreciation and amortization expense		1,004	1,074	2,017	2,150
Other noninterest expenses related to segments		27,474	27,077	56,914	52,965
Total noninterest expense		28,478	28,151	58,931	55,115
Income before income taxes		26,587	21,935	41,627	44,272
Income tax expense		5,547	4,662	8,686	9,504
Net income		21,040	17,273	32,941	34,768
Total assets		5,876,960	5,189,672	5,876,960	5,189,672	$ 5,292,659
Expenditures for long-lived assets		297	316	925	1,971
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		32,580	27,867	61,590	55,169
Provision for credit losses		2,200	525	9,236	1,175
Net interest income after provision for credit losses		30,380	27,342	52,354	53,994
Noninterest income		16,910	6,690	27,575	12,146
Depreciation and amortization expense		611	672	1,231	1,342
Other noninterest expenses related to segments		17,615	16,660	36,298	32,421
Total noninterest expense		18,226	17,332	37,529	33,763
Income before income taxes		29,064	16,700	42,400	32,377
Income tax expense		6,177	3,603	8,941	7,024
Net income		22,887	13,097	33,459	25,353
Total assets		4,579,720	3,916,915	4,579,720	3,916,915
Expenditures for long-lived assets		261	297	787	1,597
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		(26)	(120)	(93)	(247)
Provision for credit losses		0	0	0	0
Net interest income after provision for credit losses		(26)	(120)	(93)	(247)
Noninterest income		8,605	9,557	17,294	18,808
Depreciation and amortization expense		354	363	708	729
Other noninterest expenses related to segments		6,225	6,937	13,230	13,414
Total noninterest expense		6,579	7,300	13,938	14,143
Income before income taxes		2,000	2,137	3,263	4,418
Income tax expense		457	582	813	1,199
Net income		1,543	1,555	2,450	3,219
Total assets		74,803	77,757	74,803	77,757
Expenditures for long-lived assets		13	0	66	292
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)		(1,609)	6,111	2,050	13,520
Provision for credit losses		0	0	0	0
Net interest income after provision for credit losses		(1,609)	6,111	2,050	13,520
Noninterest income		805	506	1,378	1,166
Depreciation and amortization expense		39	39	78	79
Other noninterest expenses related to segments		3,634	3,480	7,386	7,130
Total noninterest expense		3,673	3,519	7,464	7,209
Income before income taxes		(4,477)	3,098	(4,036)	7,477
Income tax expense		(1,087)	477	(1,068)	1,281
Net income		(3,390)	2,621	(2,968)	6,196
Total assets		1,222,437	1,195,000	1,222,437	1,195,000
Expenditures for long-lived assets		$ 23	$ 19	$ 72	$ 82

[1] As reported in the Consolidated Statements of Income.