Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Non-controlling Interest
Beginning balance, shares at Dec. 31, 2013		6,538,000
Beginning balance, value at Dec. 31, 2013	$ 144,318	$ 6,538	$ 54,089	$ 82,855	$ 669	$ 167
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition adjustment, shares		290,000
Acquisition adjustment, value	7,446	$ 290	7,156
Cash dividend declared	(4,770)			(4,770)
Stock based compensation expense	360		360
Exercise of stock options, shares		26,000
Exercise of stock options	54	$ 26	28
Excess tax benefits from stock based payment arrangements	96		96
Distributions to noncontrolling interest	(508)					(508)
Other comprehensive income, net of tax	(422)				(422)
Net income attributable to the noncontrolling interest	459					459
Net income attributable to Northrim BanCorp, Inc.	17,408			17,408
Ending balance, value at Dec. 31, 2014	$ 164,441	$ 6,854	61,729	95,493	247	118
Ending balance, shares at Dec. 31, 2014	6,854,189	6,854,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividend declared	$ (3,806)			(3,806)
Stock based compensation expense	$ 357		357
Exercise of stock options, shares	5,162	5,000
Exercise of stock options	$ 97	$ 5	92
Excess tax benefits from stock based payment arrangements	5		5
Distributions to noncontrolling interest	(402)					(402)
Other comprehensive income, net of tax	537				537
Net income attributable to the noncontrolling interest	431					431
Net income attributable to Northrim BanCorp, Inc.	13,676			13,676
Ending balance, value at Sep. 30, 2015	$ 175,336	$ 6,859	$ 62,183	$ 105,363	$ 784	$ 147
Ending balance, shares at Sep. 30, 2015	6,859,351	6,859,000