Junior Subordinated Debentures (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2005
Subordinated Borrowing [Line Items]
Investment in unconsolidated trust	$ 54,361	$ 68,488
Junior subordinated debentures	10,310	10,310
Interest expense on deposits, borrowings and junior subordinated debentures	$ 3,779	6,051	$ 5,641
Northrim Statutory Trust 2
Subordinated Borrowing [Line Items]
Investment in unconsolidated trust				$ 10,000
Junior subordinated debentures				$ 10,300
LIBOR period	90 days
Basis plus LIBOR	1.37%
Liquidation preference per capital security (in USD per share)	$ 1,000
Interest rate	1.57%
Interest expense on deposits, borrowings and junior subordinated debentures	$ 160	$ 219	$ 398