Parent Company Information - Statements Of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income
Interest income	$ 84,606	$ 76,716	$ 70,083
Gain on sale of marketable equity securities, net	67	98	0
Unrealized (loss) gain on marketable equity securities	(101)	61	911
Other income	52,263	63,328	37,346
Expense
Interest expense	3,779	6,051	5,641
Income Before Provision for Income Taxes	47,993	42,447	26,125
Benefit from income taxes	10,476	9,559	5,434
Net income	37,517	32,888	20,691
Northrim Bancorp, Inc.
Income
Interest income	551	599	635
Gain on sale of marketable equity securities, net	67	98	0
Unrealized (loss) gain on marketable equity securities	(101)	61	911
Other income	151	10	44
Total Income	39,359	34,512	22,488
Expense
Interest expense	382	385	389
Administrative and other expenses	2,754	2,748	2,168
Total Expense	3,136	3,133	2,557
Income Before Provision for Income Taxes	36,223	31,379	19,931
Benefit from income taxes	(1,294)	(1,509)	(760)
Net income	37,517	32,888	20,691
Northrim Bancorp, Inc. | Northrim Bank
Income
Equity in undistributed earnings from subsidiaries	38,625	33,570	20,680
Northrim Bancorp, Inc. | Northrim Investment Services Company
Income
Equity in undistributed earnings from subsidiaries	$ 66	$ 174	$ 218