Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 20,004	$ 13,478	$ 14,990
Securities available for sale:
Unrealized holding gains (losses) arising during the period	(692)	175	42
Reclassification of net (gains) losses included in net income (net of tax benefit (expense) $0, $5, and ($5) in 2018, 2017 and 2016, respectively)	0	(6)	6
Derivatives and hedging activities:
Unrealized holding gains arising during the period	423	184	0
Income tax (expense) benefit related to unrealized gains and losses	210	(141)	(33)
Other comprehensive income (loss), net of tax	(59)	212	15
Comprehensive income	19,945	13,690	15,005
Less: comprehensive income attributable to the noncontrolling interest	0	327	579
Comprehensive income attributable to Northrim BanCorp, Inc.	$ 19,945	$ 13,363	$ 14,426