Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment item	Jun. 30, 2019 USD ($)
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	$ 20,091	$ 18,291	$ 38,928	$ 37,411
Provision for loan losses	3,500	1,797	6,000	4,017
Noninterest income	38,230	29,984	65,419	55,058
Noninterest expense	39,734	35,261	76,460	68,775
Net income before taxes	15,087	11,217	21,887	19,677
Corporate Administration
Key metrics related to segments
Net interest income	(856)	(908)	(1,733)	(1,817)
Noninterest income	5	1,548	9	1,552
Noninterest expense	8,533	8,429	17,721	17,075
Net income before taxes	(9,384)	(7,789)	(19,445)	(17,340)
Banking | Operating Segments
Key metrics related to segments
Net interest income	20,417	18,894	39,863	38,794
Provision for loan losses	3,500	1,797	6,000	4,017
Noninterest income	2,857	1,747	4,731	3,578
Noninterest expense	11,359	10,088	24,011	20,080
Net income before taxes	8,415	8,756	14,583	18,275
Retirement and Benefit Services | Operating Segments
Key metrics related to segments
Noninterest income	13,710	15,776	29,930	30,835
Noninterest expense	9,193	8,601	17,125	17,591
Net income before taxes	4,517	7,175	12,805	13,244
Wealth Management | Operating Segments
Key metrics related to segments
Noninterest income	4,112	3,878	8,158	7,489
Noninterest expense	2,629	2,177	4,144	4,101
Net income before taxes	1,483	1,701	4,014	3,388
Mortgage | Operating Segments
Key metrics related to segments
Net interest income	530	305	798	434
Noninterest income	17,546	7,035	22,591	11,604
Noninterest expense	8,020	5,966	13,459	9,928
Net income before taxes	$ 10,056	$ 1,374	$ 9,930	$ 2,110