Loans and Credit Quality - Narrative (Details)		12 Months Ended
	Apr. 01, 2014 USD ($) purchased_loan	Dec. 31, 2018 USD ($) financing_commitment contract	Dec. 31, 2017 USD ($) contract	Dec. 31, 2016 USD ($) contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans secured by real estate		73.00%
Loans unsecured		2.00%
Loans secured for general commercial uses		25.00%
Net nonaccrual loans		$ 14,694,000	$ 21,159,000
Interest income earned on nonaccrual loans		1,300,000	1,400,000	$ 676,000
Interest income earned on nonaccrual loans with no balance		159,000	120,000	181,000
Greater than 90 days still accruing		0	252,000
Recorded investment in loans considered to be impaired		31,714,000	31,967,000
Impaired loan, average recorded investment		34,689,000	36,895,000	42,600,000
Impaired loan, interest income on accrual method		847,000	983,000	$ 2,400,000
Loans classified as troubled debt restructuring		$ 14,831,000	23,800,000
Commitment to Lend | financing_commitment		0
Write down on TDR		$ 1,300,000	$ 731,000
TDR with specific impairment | contract		1	2
Number of Contracts | contract		6	0	0
Unfunded loan commitments		$ 15,000	$ 15,000
Loans pledged as collateral		0	0
Alaska Pacific Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased impaired loans | purchased_loan	18
Accretable difference on purchased loans	$ 0
Fair value of purchased credit impaired loans	$ 3,900,000	$ 235,000	$ 923,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recovery time for market		18 months
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recovery time for market		24 months