Segment Reporting (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment item	Sep. 30, 2019 USD ($)
Segment Reporting
Number of operating segments | segment			4
Number of Banking offices | item			15
Number of satellite offices | item			13
Key metrics related to segments
Net interest income	$ 21,765	$ 18,681	$ 60,693	$ 56,092
Provision for loan losses	3,500	1,498	9,500	5,515
Noninterest income	45,256	29,580	110,675	84,638
Noninterest expense	40,214	37,327	116,674	106,102
Net income before taxes	23,307	9,436	45,194	29,113
Corporate Administration
Key metrics related to segments
Net interest income	(842)	(896)	(2,575)	(2,713)
Noninterest income	(1)	547	8	2,099
Noninterest expense	9,112	8,885	26,833	25,960
Net income before taxes	(9,955)	(9,234)	(29,400)	(26,574)
Banking | Operating Segments
Key metrics related to segments
Net interest income	21,994	19,193	61,857	57,987
Provision for loan losses	3,500	1,498	9,500	5,515
Noninterest income	3,398	1,695	8,129	5,273
Noninterest expense	10,876	10,800	34,887	30,880
Net income before taxes	11,016	8,590	25,599	26,865
Retirement and Benefit Services | Operating Segments
Key metrics related to segments
Noninterest income	15,104	15,307	45,034	46,142
Noninterest expense	8,347	8,551	25,472	26,142
Net income before taxes	6,757	6,756	19,562	20,000
Wealth Management | Operating Segments
Key metrics related to segments
Noninterest income	4,486	3,896	12,644	11,385
Noninterest expense	2,110	1,835	6,254	5,936
Net income before taxes	2,376	2,061	6,390	5,449
Mortgage | Operating Segments
Key metrics related to segments
Net interest income	613	384	1,411	818
Noninterest income	22,269	8,135	44,860	19,739
Noninterest expense	9,769	7,256	23,228	17,184
Net income before taxes	$ 13,113	$ 1,263	$ 23,043	$ 3,373