Parent Company Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Marketable equity securities	$ 10,740	$ 8,420
Taxes receivable	1,749	1,994
Other assets	68,846	54,361
Total assets	2,674,318	2,724,719	$ 2,121,798
LIABILITIES
Junior subordinated debentures	10,310	10,310
Other liabilities	34,208	29,488
Total liabilities	2,455,689	2,486,902
SHAREHOLDERS' EQUITY
Common stock	5,701	6,015
Additional paid-in capital	17,784	31,162
Retained earnings	224,225	204,046
Accumulated other comprehensive (loss) income	(29,081)	(3,406)
Total shareholders' equity	218,629	237,817	$ 221,575	$ 207,117
Total liabilities and shareholders' equity	2,674,318	2,724,719
Northrim Bancorp, Inc.
ASSETS
Cash and cash equivalents	30,883	35,546
Marketable equity securities	10,740	8,420
Taxes receivable	463	603
Other assets	1,435	358
Total assets	229,224	249,392
LIABILITIES
Junior subordinated debentures	10,310	10,310
Other liabilities	285	1,265
Total liabilities	10,595	11,575
SHAREHOLDERS' EQUITY
Common stock	5,701	6,015
Additional paid-in capital	17,784	31,162
Retained earnings	224,225	204,046
Accumulated other comprehensive (loss) income	(29,081)	(3,406)
Total shareholders' equity	218,629	237,817
Total liabilities and shareholders' equity	229,224	249,392
Northrim Bancorp, Inc. | Northrim Bank
ASSETS
Investment in subsidiary	184,148	202,819
Northrim Bancorp, Inc. | Northrim Investment Services Company
ASSETS
Investment in subsidiary	1,245	1,336
Northrim Bancorp, Inc. | Northrim Statutory Trust 2
ASSETS
Investment in subsidiary	$ 310	$ 310