Fair Value Disclosures, Changes in Fair Value for Financial Assets (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Changes in fair value for financial assets [Abstract]
Equity Securities at fair value, net gains (losses)	$ 167	$ (154)
Loans held for sale, net gains (losses)	96	(153)
Capitalized mortgage loan servicing rights, net gains (losses)	(2,691)	1,029
Impairment charges recognized [Abstract]
Collateral dependent loans, carrying amount	3,700		$ 3,500
Collateral dependent loans, valuation allowance	1,700		1,500
Additional provision for loan losses on impaired loans	500	100
Other real estate, carrying amount	200		200
Other real estate, valuation allowance	300		$ 100
Other real estate, additional charge	120	20
Securities [Member]
Changes in fair value for financial assets [Abstract]
Equity Securities at fair value, net gains (losses)	167	(154)
Mortgage Loans [Member]
Changes in fair value for financial assets [Abstract]
Loans held for sale, net gains (losses)	96	(153)
Mortgage Loan Servicing, Net [Member]
Changes in fair value for financial assets [Abstract]
Capitalized mortgage loan servicing rights, net gains (losses)	$ (2,691)	$ 1,029

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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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

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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.

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Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable.

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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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