Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net income	$ 13,478	$ 14,990	$ 18,334
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Loss (gain) on sale of securities, net	(11)	11	(271)
Loss on sale of premises and equipment	3	352	37
Gain on sale of Northrim Benefits Group	(4,445)	0	0
Depreciation and amortization of premises and equipment	2,867	2,439	2,264
Amortization of software	675	157	179
Intangible asset amortization	100	135	258
Amortization of investment security premium, net of discount accretion	332	27	(202)
Deferred tax expense (benefit)	4,004	(325)	148
Stock-based compensation	665	778	608
Excess tax expense (benefit) from share-based payment arrangements	0	63	(56)
Deferral of loan fees and costs, net	(278)	(178)	61
Provision for loan losses	3,200	2,298	1,754
Reserve (benefit) for purchased receivables	29	(10)	(138)
Additions to mortgage servicing rights carried at fair value	(3,146)	(3,029)	(802)
Change in fair value of mortgage servicing rights carried at fair value	(2)	526	158
Gain on sale of loans	(18,013)	(25,413)	(26,398)
Proceeds from the sale of loans held for sale	571,909	768,169	773,526
Origination of loans held for sale	(554,078)	(735,799)	(753,815)
Gain on sale of other real estate owned	(371)	(295)	(315)
Impairment on other real estate owned	904	187	361
Impairment on equity method investment	686	0	0
Net changes in assets and liabilities:
Increase in accrued interest receivable	(651)	(114)	(247)
(Increase) decrease in other assets	841	10,015	6,232
Increase (decrease) in other liabilities	586	(14,861)	(11,041)
Net Cash Provided by Operating Activities	19,284	20,123	10,635
Investment in securities:
Purchases of investment securities available for sale	(84,339)	(145,707)	(210,308)
Purchases of FHLB stock	(3,665)	(751)	0
Proceeds from sales/calls/maturities of securities available for sale	102,660	105,621	200,343
Proceeds from calls/maturities of securities held to maturity	890	0	1,285
Proceeds from maturities of domestic certificates of deposit	0	0	3,500
Proceeds from redemption of FHLB stock	3,515	602	1,588
(Increase) decrease in purchased receivables, net	(1,769)	(7,155)	2,066
Decrease (increase) in loans, net	12,278	1,160	(57,927)
Proceeds from sale of other real estate owned	3,302	934	2,733
Proceeds from the sale of Northrim Benefits Group	4,625	0	0
Investment in other real estate owned	0	(311)	0
Elliott Cove divestiture, net of cash received	0	0	219
Purchases of software	(5,680)	0	(116)
Proceeds from sales of premises and equipment	116	1,401	188
Purchases of premises and equipment	(1,555)	(3,293)	(7,026)
Net Cash Provided (Used) by Investing Activities	30,378	(47,499)	(63,455)
Financing Activities:
Increase (decrease) in deposits	(9,370)	26,861	61,045
Increase (decrease) in securities sold under repurchase agreements	139	(3,813)	11,577
Proceeds from borrowings	3,097	2,265	0
Repayments of borrowings	(73)	(47)	(24,184)
Distributions to noncontrolling interest	(445)	(640)	(490)
Repayment of junior subordinated debentures	(8,248)	0	0
Proceeds from the issuance of common stock	100	0	50
Repurchase of common stock	(1,607)	0	0
Excess tax benefits from share-based payment arrangements	0	0	56
Cash dividends paid	(5,965)	(5,372)	(5,117)
Net Cash (Used) Provided by Financing Activities	(22,372)	19,254	42,937
Net Change in Cash and Cash Equivalents	27,290	(8,122)	(9,883)
Cash and Cash Equivalents at Beginning of Year	50,551	58,673	68,556
Cash and Cash Equivalents at End of Year	77,841	50,551	58,673
Supplemental Information:
Income taxes paid	7,764	4,414	5,674
Interest paid	2,470	2,553	2,833
Noncash commitments to invest in Low Income Housing Tax Credit Partnerships	0	6,809	55
Transfer of loans to other real estate owned	5,912	4,036	1,259
Cash dividends declared but not paid	$ 53	$ 48	$ 46