Investment Securities - Textual (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Amortized Cost	$ 227,154,000		$ 229,189,000
Fair Value	232,918,000		232,917,000
Accrued Investment Income Receivable	3,900,000		3,700,000
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale		$ 0
Securities classified as trading	0		0
Available-for-sale Securities [Member]
Provision for Other Credit Losses	0
Repurchase Agreements [Member]
Amortized Cost	26,420,000		22,156,000
Fair Value	26,473,000		22,294,000
Washington and Oregon State to Secure Public Deposits [Member]
Amortized Cost	179,570,000		187,700,000
Fair Value	184,231,000		190,773,000
Other securities pledged
Amortized Cost	21,164,000		19,333,000
Fair Value	$ 22,214,000		$ 19,850,000

Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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