Quarterly Results Of Operations (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Data [Abstract]
Total interest income	$ 12,018	$ 11,524	$ 11,440	$ 11,092	$ 11,349	$ 11,204	$ 11,123	$ 11,052	$ 46,074	$ 44,728	$ 45,908
Total interest expense	497	502	511	530	569	611	627	698	2,040	2,505	3,544
Net Interest Income	11,521	11,022	10,929	10,562	10,780	10,593	10,496	10,354	44,034	42,223	42,364
Provision (benefit) for loan losses	0	(785)	0	150	(300)	(1,437)	89	89	(635)	(1,559)	1,999
Other operating income	2,802	3,243	3,702	3,139	4,343	4,157	3,725	3,207	12,886	15,432	13,090
Other operating expense	10,702	10,076	9,391	9,697	10,555	9,992	9,295	9,758	39,866	39,600	36,755
Income Before Provision for Income Taxes	3,621	4,974	5,240	3,854	4,868	6,195	4,837	3,714	17,689	19,614	16,700
Provision for income taxes	1,042	1,510	1,635	1,090	1,588	1,991	1,551	1,026	5,277	6,156	4,873
Net income	2,579	3,464	3,605	2,764	3,280	4,204	3,286	2,688	12,412	13,458	11,827
Less: Net income attributable to the noncontrolling interest	(102)	(10)	109	90	118	138	144	112	87	512	429
Net Income Attributable to Northrim BanCorp	$ 2,681	$ 3,474	$ 3,496	$ 2,674	$ 3,162	$ 4,066	$ 3,142	$ 2,576	$ 12,325	$ 12,946	$ 11,398
Earnings Per Share, Basic	$ 0.41	$ 0.53	$ 0.54	$ 0.41	$ 0.49	$ 0.63	$ 0.49	$ 0.40	$ 1.89	$ 2.00	$ 1.77
Earnings per share, diluted	$ 0.40	$ 0.53	$ 0.53	$ 0.41	$ 0.48	$ 0.62	$ 0.48	$ 0.39	$ 1.87	$ 1.97	$ 1.74