Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest
Beginning balance (in 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]
Purchase of Alaska Pacific (in shares)		290,000
Purchase of Alaska Pacific	7,446	$ 290	7,156
Cash dividend declared	(4,770)			(4,770)
Stock-based compensation expense	360		360
Exercise of stock options and vesting of restricted stock units, net (in shares)		26,000
Exercise of stock options and vesting of restricted stock units, net	54	$ 26	28
Excess tax benefits from share-based payment arrangements	96		96
Distributions to noncontrolling interest	(508)					(508)
Other comprehensive income (loss), 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 (in shares) at Dec. 31, 2014		6,854,000
Ending balance, value at Dec. 31, 2014	164,441	$ 6,854	61,729	95,493	247	118
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividend declared	(5,126)			(5,126)
Stock-based compensation expense	608		608
Exercise of stock options and vesting of restricted stock units, net (in shares)		23,000
Exercise of stock options and vesting of restricted stock units, net	50	$ 23	27
Excess tax benefits from share-based payment arrangements	56		56
Distributions to noncontrolling interest	(490)					(490)
Other comprehensive income (loss), net of tax	(659)				(659)
Net income attributable to the noncontrolling interest	551					551
Net income attributable to Northrim BanCorp, Inc.	$ 17,783			17,783
Ending balance (in shares) at Dec. 31, 2015	6,877,140	6,877,000
Ending balance, value at Dec. 31, 2015	$ 177,214	$ 6,877	62,420	108,150	(412)	179
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividend declared	(5,420)			(5,420)
Stock-based compensation expense	778		778
Exercise of stock options and vesting of restricted stock units, net (in shares)		21,000
Exercise of stock options and vesting of restricted stock units, net	(162)	$ 21	(183)
Excess tax benefits from share-based payment arrangements	(63)		(63)
Distributions to noncontrolling interest	(640)					(640)
Other comprehensive income (loss), net of tax	15				15
Net income attributable to the noncontrolling interest	579					579
Net income attributable to Northrim BanCorp, Inc.	$ 14,411			14,411
Ending balance (in shares) at Dec. 31, 2016	6,897,890	6,898,000
Ending balance, value at Dec. 31, 2016	$ 186,712	$ 6,898	$ 62,952	$ 117,141	$ (397)	$ 118