Segment Reporting (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($) segment item	Mar. 31, 2019 USD ($)
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	$ 18,837	$ 19,120
Provision for loan losses	2,500	2,220
Noninterest income	27,189	25,074
Noninterest expense	36,726	33,514
Net income before taxes	6,800	8,460
Corporate Administration
Key metrics related to segments
Net interest income	(877)	(909)
Noninterest income	4	4
Noninterest expense	9,188	8,646
Net income before taxes	(10,061)	(9,551)
Banking \| Operating Segments
Key metrics related to segments
Net interest income	19,446	19,900
Provision for loan losses	2,500	2,220
Noninterest income	1,874	1,831
Noninterest expense	12,652	9,992
Net income before taxes	6,168	9,519
Retirement and Benefit Services \| Operating Segments
Key metrics related to segments
Noninterest income	16,220	15,059
Noninterest expense	7,932	8,990
Net income before taxes	8,288	6,069
Wealth Management \| Operating Segments
Key metrics related to segments
Noninterest income	4,046	3,611
Noninterest expense	1,515	1,924
Net income before taxes	2,531	1,687
Mortgage \| Operating Segments
Key metrics related to segments
Net interest income	268	129
Noninterest income	5,045	4,569
Noninterest expense	5,439	3,962
Net income before taxes	$ (126)	$ 736

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Number of satellite offices.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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The net amount of operating interest income (expense).

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Amount of expense related to estimated loss from loan and lease transactions.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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