Parent Company Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
ASSETS
Marketable equity securities	$ 8,392	$ 8,719
Taxes receivable, net	1,751	1,984
Other assets	84,172	85,819
Total assets	3,290,273	3,041,869	$ 2,807,497
LIABILITIES
Subordinated debentures	68,924	10,310
Other liabilities	63,030	53,722
Total liabilities	2,963,729	2,774,753
SHAREHOLDERS' EQUITY
Common stock	5,528	5,518
Additional paid-in capital	10,822	9,311
Retained earnings	309,575	259,311
Accumulated other comprehensive (loss) income	619	(7,024)
Total shareholders' equity	326,544	267,116	$ 234,718	$ 218,629
Total liabilities and shareholders' equity	3,290,273	3,041,869
Northrim Bancorp, Inc.
ASSETS
Cash and cash equivalents	14,952	4,387
Marketable equity securities	8,392	8,719
Taxes receivable, net	3,051	0
Other assets	2,703	2,233
Total assets	396,472	277,718
LIABILITIES
Subordinated debentures	68,924	10,310
Other liabilities	1,004	292
Total liabilities	69,928	10,602
SHAREHOLDERS' EQUITY
Common stock	5,528	5,518
Additional paid-in capital	10,822	9,311
Retained earnings	309,575	259,311
Accumulated other comprehensive (loss) income	619	(7,024)
Total shareholders' equity	326,544	267,116
Total liabilities and shareholders' equity	396,472	277,718
Northrim Bancorp, Inc. | Northrim Bank
ASSETS
Investment in subsidiary	362,036	260,957
Northrim Bancorp, Inc. | Northrim Investment Services Company
ASSETS
Investment in subsidiary	5,028	1,112
Northrim Bancorp, Inc. | Northrim Statutory Trust 2
ASSETS
Investment in subsidiary	$ 310	$ 310