Parent Company Information - Statements Of Income (Details) (USD $) In Thousands, 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
Interest income	$ 12,018	$ 11,524	$ 11,440	$ 11,092	$ 11,349	$ 11,204	$ 11,123	$ 11,052	$ 46,074	$ 44,728	$ 45,908
Other income	2,802	3,243	3,702	3,139	4,343	4,157	3,725	3,207	12,886	15,432	13,090
Interest expense	497	502	511	530	569	611	627	698	2,040	2,505	3,544
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 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
Northrim Bancorp, Inc.
Interest income									208	198	51
Other income									170	209	92
Total Income									14,060	14,392	12,602
Interest expense									459	493	466
Administrative and other expenses									2,387	1,646	1,737
Total Expense									2,846	2,139	2,203
Income Before Provision for Income Taxes									11,214	12,253	10,399
Provision for income taxes									(1,111)	(693)	(999)
Net Income Attributable to Northrim BanCorp									12,325	12,946	11,398
Northrim Bank | Northrim Bancorp, Inc.
Net income from subsidiary									13,645	13,950	12,442
Northrim Investment Services Company | Northrim Bancorp, Inc.
Net income from subsidiary									$ 37	$ 35	$ 17