Consolidated Statements Of Changes In Shareholders' Equity And Comprehensive Income (USD $) In Thousands, except Share data	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, 2010	$ 6,427	$ 52,658	$ 57,339	$ 648	$ 50	$ 117,122
Beginning balance, shares at Dec. 31, 2010	6,427,000
Cash dividend declared			(1,564)			(1,564)
Stock based compensation expense		263				263
Exercise of stock options, shares	6,000
Exercise of stock options	6	(6)
Excess tax benefits from share-based payment arrangements		38				38
Distributions to noncontrolling interest					(230)	(230)
Change in unrealized holding gain on available for sale securities, net of tax				521		521
Net income attributable to the noncontrolling interest					222	222
Net income attributable to Northrim BanCorp			5,637			5,637
Ending balance, value at Jun. 30, 2011	6,433	52,953	61,412	1,169	42	122,009
Ending balance, shares at Jun. 30, 2011	6,433,000					6,433,438
Beginning balance, value at Dec. 31, 2011	6,467	53,164	65,469	283	52	125,435
Beginning balance, shares at Dec. 31, 2011	6,467,000					6,466,763
Cash dividend declared			(1,705)			(1,705)
Stock based compensation expense		225				225
Exercise of stock options, shares	4,000
Exercise of stock options	4	(6)				(2)
Excess tax benefits from share-based payment arrangements		28				28
Distributions to noncontrolling interest					(231)	(231)
Change in unrealized holding gain on available for sale securities, net of tax				701		701
Net income attributable to the noncontrolling interest					256	256
Net income attributable to Northrim BanCorp			5,718			5,718
Ending balance, value at Jun. 30, 2012	$ 6,471	$ 53,411	$ 69,482	$ 984	$ 77	$ 130,425
Ending balance, shares at Jun. 30, 2012	6,471,000					6,470,518