Loans and Allowance for Credit Losses - Portfolio of Risk-rated Loans by Grade and by Year of Origination (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	$ 322,555	$ 518,711
2024/2023	445,951	392,844
2023/2022	317,339	459,993
2022/2021	425,109	237,890
2021/2020	194,334	169,547
Prior	513,682	350,278
Amortized Cost	2,218,970	2,129,263
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	313,211	518,510
2024/2023	442,167	388,836
2023/2022	309,015	441,442
2022/2021	402,931	222,887
2021/2020	184,080	163,440
Prior	483,988	321,665
Amortized Cost	2,135,392	2,056,780
Pass \| Government guarantees
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	12,013	35,244
2024/2023	34,650	12,421
2023/2022	19,438	7,727
2022/2021	4,818	13,785
2021/2020	11,325	1,591
Prior	14,465	17,276
Amortized Cost	96,709	88,044
Pass \| Net of government guarantees
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	301,198	483,266
2024/2023	407,517	376,415
2023/2022	289,577	433,715
2022/2021	398,113	209,102
2021/2020	172,755	161,849
Prior	469,523	304,389
Amortized Cost	2,038,683	1,968,736
Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	9,344	201
2024/2023	3,784	4,008
2023/2022	8,324	18,551
2022/2021	22,178	15,003
2021/2020	10,254	6,107
Prior	29,694	28,613
Amortized Cost	83,578	72,483
Criticized \| Government guarantees
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	1,640
2023/2022	1,686	14,816
2022/2021	16,939	13,476
2021/2020	8,923	5,183
Prior	12,555	7,963
Amortized Cost	40,103	43,078
Criticized \| Net of government guarantees
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	9,344	201
2024/2023	3,784	2,368
2023/2022	6,638	3,735
2022/2021	5,239	1,527
2021/2020	1,331	924
Prior	17,139	20,650
Amortized Cost	43,475	29,405
Commercial & industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	82,145	112,562
2024/2023	96,050	74,257
2023/2022	68,916	137,265
2022/2021	119,208	52,601
2021/2020	36,839	16,340
Prior	71,691	44,897
Amortized Cost	474,849	437,922
Commercial & industrial loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	78,803	112,361
2024/2023	92,276	70,871
2023/2022	61,482	120,377
2022/2021	102,490	37,628
2021/2020	26,749	10,581
Prior	65,082	40,288
Amortized Cost	426,882	392,106
Commercial & industrial loans \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	3,342	201
2024/2023	3,774	3,386
2023/2022	7,434	16,888
2022/2021	16,718	14,973
2021/2020	10,090	5,759
Prior	6,609	4,609
Amortized Cost	47,967	45,816
Commercial real estate \| Owner occupied properties
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	34,763	68,074
2024/2023	76,787	48,655
2023/2022	26,643	75,103
2022/2021	72,168	64,234
2021/2020	58,411	75,010
Prior	169,223	87,016
Amortized Cost	437,995	418,092
Commercial real estate \| Owner occupied properties \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	28,761	68,074
2024/2023	76,787	48,655
2023/2022	26,643	74,611
2022/2021	68,454	64,234
2021/2020	58,411	74,662
Prior	157,679	74,987
Amortized Cost	416,735	405,223
Commercial real estate \| Owner occupied properties \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	6,002	0
2024/2023	0	0
2023/2022	0	492
2022/2021	3,714	0
2021/2020	0	348
Prior	11,544	12,029
Amortized Cost	21,260	12,869
Commercial real estate \| Non-owner occupied and multifamily properties
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	86,594	114,879
2024/2023	119,808	70,806
2023/2022	67,965	106,090
2022/2021	140,520	73,038
2021/2020	68,335	65,592
Prior	230,093	185,257
Amortized Cost	713,315	615,662
Commercial real estate \| Non-owner occupied and multifamily properties \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	86,594	114,879
2024/2023	119,808	70,806
2023/2022	67,965	104,924
2022/2021	139,372	73,008
2021/2020	68,335	65,592
Prior	220,286	175,349
Amortized Cost	702,360	604,558
Commercial real estate \| Non-owner occupied and multifamily properties \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	1,166
2022/2021	1,148	30
2021/2020	0	0
Prior	9,807	9,908
Amortized Cost	10,955	11,104
Residential real estate \| 1-4 family residential properties secured by first liens
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	34,925	103,919
2024/2023	56,016	108,847
2023/2022	78,638	43,562
2022/2021	34,263	3,279
2021/2020	2,596	4,228
Prior	10,160	7,131
Amortized Cost	216,598	270,966
Residential real estate \| 1-4 family residential properties secured by first liens \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	34,925	103,919
2024/2023	56,016	108,642
2023/2022	78,120	43,562
2022/2021	33,950	3,279
2021/2020	2,596	4,228
Prior	9,983	6,978
Amortized Cost	215,590	270,608
Residential real estate \| 1-4 family residential properties secured by first liens \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	205
2023/2022	518	0
2022/2021	313	0
2021/2020	0	0
Prior	177	153
Amortized Cost	1,008	358
Residential real estate \| 1-4 family residential properties secured by junior liens and revolving secured by 1-4 family first liens
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	19,204	18,946
2024/2023	20,059	13,925
2023/2022	11,250	5,116
2022/2021	5,726	2,695
2021/2020	2,947	2,097
Prior	7,093	6,381
Amortized Cost	66,279	49,160
Residential real estate \| 1-4 family residential properties secured by junior liens and revolving secured by 1-4 family first liens \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	19,204	18,946
2024/2023	20,059	13,553
2023/2022	10,878	5,116
2022/2021	5,726	2,695
2021/2020	2,947	2,097
Prior	7,004	6,083
Amortized Cost	65,818	48,490
Residential real estate \| 1-4 family residential properties secured by junior liens and revolving secured by 1-4 family first liens \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	372
2023/2022	372	0
2022/2021	0	0
2021/2020	0	0
Prior	89	298
Amortized Cost	461	670
Residential real estate \| 1-4 family residential construction loans
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	19,745	25,458
2024/2023	7,232	4,118
2023/2022	0	2,353
2022/2021	0	0
2021/2020	0	0
Prior	10,261	7,587
Amortized Cost	37,238	39,516
Residential real estate \| 1-4 family residential construction loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	19,745	25,458
2024/2023	7,232	4,118
2023/2022	0	2,353
2022/2021	0	0
2021/2020	0	0
Prior	10,261	7,587
Amortized Cost	37,238	39,516
Residential real estate \| 1-4 family residential construction loans \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	0
2022/2021	0	0
2021/2020	0	0
Prior	0	0
Amortized Cost	0	0
Other construction, land development and raw land loans
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	40,608	63,430
2024/2023	55,620	60,693
2023/2022	53,712	51,809
2022/2021	14,831	25,836
2021/2020	9,300	1,236
Prior	9,010	9,557
Amortized Cost	183,081	212,561
Other construction, land development and raw land loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	40,608	63,430
2024/2023	55,620	60,693
2023/2022	53,712	51,809
2022/2021	14,549	25,836
2021/2020	9,273	1,236
Prior	7,542	7,942
Amortized Cost	181,304	210,946
Other construction, land development and raw land loans \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	0
2022/2021	282	0
2021/2020	27	0
Prior	1,468	1,615
Amortized Cost	1,777	1,615
Obligations of states and political subdivisions in the US
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	4,389	0
2023/2022	0	29,471
2022/2021	27,952	0
2021/2020	0	0
Prior	0	0
Amortized Cost	32,341	29,471
Obligations of states and political subdivisions in the US \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	4,389	0
2023/2022	0	29,471
2022/2021	27,952	0
2021/2020	0	0
Prior	0	0
Amortized Cost	32,341	29,471
Obligations of states and political subdivisions in the US \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	0
2022/2021	0	0
2021/2020	0	0
Prior	0	0
Amortized Cost	0	0
Agricultural production, including commercial fishing
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	1,601	8,097
2024/2023	7,995	8,776
2023/2022	8,189	8,380
2022/2021	9,817	15,847
2021/2020	15,592	3,109
Prior	3,931	1,631
Amortized Cost	47,125	45,840
Agricultural production, including commercial fishing \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	1,601	8,097
2024/2023	7,995	8,776
2023/2022	8,189	8,380
2022/2021	9,817	15,847
2021/2020	15,455	3,109
Prior	3,931	1,631
Amortized Cost	46,988	45,840
Agricultural production, including commercial fishing \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	0
2022/2021	0	0
2021/2020	137	0
Prior	0	0
Amortized Cost	137	0
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	2,970	3,346
2024/2023	1,995	2,422
2023/2022	1,791	722
2022/2021	545	75
2021/2020	37	252
Prior	997	821
Amortized Cost	8,335	7,638
Consumer loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	2,970	3,346
2024/2023	1,985	2,377
2023/2022	1,791	717
2022/2021	542	75
2021/2020	37	252
Prior	997	820
Amortized Cost	8,322	7,587
Consumer loans \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	10	45
2023/2022	0	5
2022/2021	3	0
2021/2020	0	0
Prior	0	1
Amortized Cost	13	51
Other loans
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	345
2023/2022	235	122
2022/2021	79	285
2021/2020	277	1,683
Prior	1,223	0
Amortized Cost	1,814	2,435
Other loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	345
2023/2022	235	122
2022/2021	79	285
2021/2020	277	1,683
Prior	1,223	0
Amortized Cost	1,814	2,435
Other loans \| Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	0	0
2024/2023	0	0
2023/2022	0	0
2022/2021	0	0
2021/2020	0	0
Prior	0	0
Amortized Cost	$ 0	$ 0

NORTHRIM BANCORP INC 10-Q