Parent Company Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
ASSETS
Marketable equity securities	$ 8,719	$ 13,153
Taxes receivable, net	1,984	1,726
Other assets	85,819	71,789
Total assets	3,041,869	2,807,497	$ 2,674,318
LIABILITIES
Junior subordinated debentures	10,310	10,310
Other liabilities	53,722	54,647
Total liabilities	2,774,753	2,572,779
SHAREHOLDERS' EQUITY
Common stock	5,518	5,513
Additional paid-in capital	9,311	9,605
Retained earnings	259,311	236,037
Accumulated other comprehensive (loss) income	(7,024)	(16,437)
Total shareholders' equity	267,116	234,718	$ 218,629	$ 237,817
Total liabilities and shareholders' equity	3,041,869	2,807,497
Northrim Bancorp, Inc.
ASSETS
Cash and cash equivalents	4,387	19,055
Marketable equity securities	8,719	13,153
Taxes receivable, net	0	1,212
Other assets	2,233	2,152
Total assets	277,718	245,484
LIABILITIES
Junior subordinated debentures	10,310	10,310
Other liabilities	292	456
Total liabilities	10,602	10,766
SHAREHOLDERS' EQUITY
Common stock	5,518	5,513
Additional paid-in capital	9,311	9,605
Retained earnings	259,311	236,037
Accumulated other comprehensive (loss) income	(7,024)	(16,437)
Total shareholders' equity	267,116	234,718
Total liabilities and shareholders' equity	277,718	245,484
Northrim Bancorp, Inc. | Northrim Bank
ASSETS
Investment in subsidiary	260,957	208,435
Northrim Bancorp, Inc. | Northrim Investment Services Company
ASSETS
Investment in subsidiary	1,112	1,167
Northrim Bancorp, Inc. | Northrim Statutory Trust 2
ASSETS
Investment in subsidiary	$ 310	$ 310