Note 19 - Parent Only Condensed Financial Statements - Condensed Statements of Income and Comprehensive Income (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gain on termination of swaps		$ 1,707,000	$ 0	$ 0
Interest on junior subordinated deferrable interest debentures		141,000	359,000	348,000
Interest on borrowings		896,000	0	0
Other expenses		31,000	67,000	8,000
Total interest expense		4,798,000	1,249,000	1,136,000
Income before income taxes		40,211,000	35,669,000	28,487,000
Income tax (expense) benefit		(10,435,000)	(9,225,000)	(7,478,000)
Net income	$ 29,776,000	29,776,000	26,444,000	21,009,000
Total comprehensive income (loss)		34,068,000	(11,912,000)	17,864,000
Parent Company [Member]
Dividends declared by bank subsidiary		7,500,000	4,000,000	8,035,000
Gain on termination of swaps		1,707,000	0	0
Earnings from investment in Plumas Statutory Trust I and II		5,000	14,000	9,000
Total income		9,212,000	4,014,000	8,044,000
Interest on junior subordinated deferrable interest debentures		141,000	359,000	348,000
Interest on borrowings		369,000	0	0
Other expenses		523,000	556,000	399,000
Total interest expense		1,033,000	915,000	747,000
Income before equity in undistributed income of subsidiary		8,179,000	3,099,000	7,297,000
Equity in undistributed income of subsidiary		21,746,000	23,039,000	13,442,000
Income before income taxes		29,925,000	26,138,000	20,739,000
Income tax (expense) benefit		(149,000)	306,000	270,000
Net income		29,776,000	26,444,000	21,009,000
Total comprehensive income (loss)		$ 34,068,000	$ (11,912,000)	$ 17,864,000