Consolidated Statements Of Changes In Shareholders' Equity And Comprehensive Income (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest [Member]	Total
Beginning balance, value at Dec. 31, 2008	$ 6,331	$ 51,458	$ 45,958	$ 901	$ 36	$ 104,684
Beginning balance, shares at Dec. 31, 2008	6,331,000
Cash dividend declared			(2,564)			(2,564)
Stock option expense		648				648
Exercise of stock options, shares	40,000
Exercise of stock options	40	7				47
Excess tax benefits from share-based payment arrangements		26				26
Distributions to noncontrolling interest					(376)	(376)
Comprehensive income:
Change in unrealized holding gain/(loss) on available for sale investment securities, net of related income tax effect				440		440
Net Income attributable to the noncontrolling interest					388	388
Net Income attributable to Northrim Bancorp			7,727			7,727
Total Comprehensive Income						8,167
Ending balance, value at Dec. 31, 2009	6,371	52,139	51,121	1,341	48	111,020
Ending balance, shares at Dec. 31, 2009	6,371,000
Cash dividend declared			(2,848)			(2,848)
Stock option expense		466				466
Exercise of stock options, shares	56,000
Exercise of stock options	56	(132)				(76)
Excess tax benefits from share-based payment arrangements		185				185
Distributions to noncontrolling interest					(397)	(397)
Comprehensive income:
Change in unrealized holding gain/(loss) on available for sale investment securities, net of related income tax effect				(693)		(693)
Net Income attributable to the noncontrolling interest					399	399
Net Income attributable to Northrim Bancorp			9,066			9,066
Total Comprehensive Income						8,373
Ending balance, value at Dec. 31, 2010	6,427	52,658	57,339	648	50	117,122
Ending balance, shares at Dec. 31, 2010	6,427,000					6,427,237
Cash dividend declared			(3,268)			(3,268)
Stock option expense		519				519
Exercise of stock options, shares	40,000
Exercise of stock options	40	(184)				(144)
Excess tax benefits from share-based payment arrangements		171				171
Distributions to noncontrolling interest					(427)	(427)
Comprehensive income:
Change in unrealized holding gain/(loss) on available for sale investment securities, net of related income tax effect				(365)		(365)
Net Income attributable to the noncontrolling interest					429	429
Net Income attributable to Northrim Bancorp			11,398			11,398
Total Comprehensive Income						11,033
Ending balance, value at Dec. 31, 2011	$ 6,467	$ 53,164	$ 65,469	$ 283	$ 52	$ 125,435
Ending balance, shares at Dec. 31, 2011	6,467,000					6,466,763