Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 34,584	$ 31,852
Provision for loan losses	650	0
Net interest income after provision for loan losses	33,934	31,852
Noninterest income	15,367	15,743
Depreciation and amortization expense	1,077	1,075
Other noninterest expenses related to segments	25,887	26,055
Total noninterest expense	26,964	27,130
Income before income taxes	22,337	20,465
Income tax expense	4,842	4,254
Net income	17,495	16,211
Total assets	5,154,729	4,566,326	$ 5,010,766
Expenditures for long-lived assets	1,655	811
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	27,302	25,976
Provision for loan losses	650	0
Net interest income after provision for loan losses	26,652	25,976
Noninterest income	5,455	4,936
Depreciation and amortization expense	672	637
Other noninterest expenses related to segments	15,758	15,466
Total noninterest expense	16,430	16,103
Income before income taxes	15,677	14,809
Income tax expense	3,421	3,103
Net income	12,256	11,706
Total assets	3,884,052	3,521,309
Expenditures for long-lived assets	1,300	598
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(127)	(58)
Provision for loan losses	0	0
Net interest income after provision for loan losses	(127)	(58)
Noninterest income	9,252	10,273
Depreciation and amortization expense	365	396
Other noninterest expenses related to segments	6,478	7,199
Total noninterest expense	6,843	7,595
Income before income taxes	2,282	2,620
Income tax expense	617	643
Net income	1,665	1,977
Total assets	76,657	66,567
Expenditures for long-lived assets	292	154
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	7,409	5,934
Provision for loan losses	0	0
Net interest income after provision for loan losses	7,409	5,934
Noninterest income	660	534
Depreciation and amortization expense	40	42
Other noninterest expenses related to segments	3,651	3,390
Total noninterest expense	3,691	3,432
Income before income taxes	4,378	3,036
Income tax expense	804	508
Net income	3,574	2,528
Total assets	1,194,020	978,450
Expenditures for long-lived assets	$ 63	$ 59