Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 20,691	$ 20,004	$ 13,478
Securities available for sale:
Unrealized holding gains (losses) arising during the period	2,866	(692)	175
Reclassification of net gains included in net income (net of tax expense of $7, $0, and $5 in 2019, 2018 and 2017, respectively)	(16)	0	(6)
Derivatives and hedging activities:
Unrealized holding (losses) gains arising during the period	(1,142)	423	184
Income tax (expense) benefit related to unrealized gains and losses	(757)	210	(141)
Other comprehensive income (loss), net of tax	951	(59)	212
Comprehensive income	21,642	19,945	13,690
Less: comprehensive income attributable to the noncontrolling interest	0	0	327
Comprehensive income attributable to Northrim BanCorp, Inc.	$ 21,642	$ 19,945	$ 13,363