Fair Value Disclosures, Changes in Fair Value for Financial Assets (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Changes in fair value for financial assets [Abstract]
Loans held for sale	$ (2,598)	$ 523
Capitalized mortgage loan servicing rights, net gains (losses)	3,257	(6,974)
Impairment charges recognized [Abstract]
Collateral dependent loans, carrying amount	2,900		$ 9,100
Collateral dependent loans, valuation allowance	1,500		1,800
Additional provision for credit losses on collateral dependent loans	200	2,400
Other real estate, carrying amount	0		100
Other real estate, valuation allowance	60		$ 90
Other real estate, additional charge	0	90
Mortgage Loans [Member]
Changes in fair value for financial assets [Abstract]
Loans held for sale	(2,598)	523
Mortgage Loan Servicing, Net [Member]
Changes in fair value for financial assets [Abstract]
Capitalized mortgage loan servicing rights, net gains (losses)	$ 3,257	$ (6,974)

Loans which are measured for impairment using the fair value of collaterals.

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- Definition

The valuation allowance on loans measured for impairment, using the fair value of collaterals.

+ References

No definition available.

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- Definition

Amount of unrealized gain (loss) on loans held for sale measured at fair value with change in fair value recognized in net income.

+ References

No definition available.

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Carrying amount of other real estate that are impaired, net reserves.

+ References

No definition available.

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Amount of unrealized gain (loss) on capitalized servicing rights measured at fair value with change in fair value recognized in net income.

+ References

No definition available.

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

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Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 326
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For each period for which an income statement is required, disclosure of the changes in the allowance, including balances at end of period.

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