Parent Company Information (Statements Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 12,946	$ 11,398	$ 9,066
Stock-based compensation	454	519	466
Net Cash Provided by Operating Activities	32,549	(5,025)	18,106
Investment in securities available for sale	(111,431)	(169,712)	(236,299)
Net Cash (Used) Provided by Investing Activities	(28,276)	216	(60,722)
Dividends paid to shareholders	(3,676)	(3,264)	(2,828)
Net Cash Provided by Financing Activities	57,510	18,306	41,928
Net Increase by Cash and Cash Equivalents	61,783	13,497	(688)
Cash and Cash Equivalents at Beginning of Period	79,530	66,033	66,721
Cash and Cash Equivalents at End of Period	141,313	79,530	66,033
Northrim Bancorp, Inc. [Member]
Net income	12,946	11,398	9,066
Equity in undistributed earnings from subsidiaries	(13,985)	(12,461)	(10,076)
Stock-based compensation	454	519	466
Changes in other assets and liabilities	79	(852)	(568)
Net Cash Provided by Operating Activities	(506)	(1,396)	(1,112)
Investment in securities available for sale	(2,527)	(999)
Investment in Northrim Bank, NISC, NCT1 & NST2	(7,921)	(7,040)	(4,307)
Net Cash (Used) Provided by Investing Activities	5,394	6,041	4,307
Dividends paid to shareholders	(3,676)	(3,264)	(2,848)
Proceeds from issuance of common stock and excess tax benefits	233	171	185
Net Cash Provided by Financing Activities	(3,443)	(3,093)	(2,663)
Net Increase by Cash and Cash Equivalents	1,445	1,552	532
Cash and Cash Equivalents at Beginning of Period	7,304	5,752	5,220
Cash and Cash Equivalents at End of Period	$ 8,749	$ 7,304	$ 5,752