Note 10 - Junior Subordinated Deferrable Interest Debentures (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2005	Dec. 31, 2002
Capital	$ 97,810,000	$ 83,753,000
Interest Expense, Junior Subordinated Debentures	531,000	$ 510,000	$ 401,000
Plumas Statutory Trust I [Member]
Capital	$ 349,000
Trust Preferred Securities Issued, Number					6,000
Trust Preferred Securities, Liquidation Amount per Preferred Security					$ 1,000
Proceeds from Issuance of Trust Preferred Securities					$ 6,000,000
Amount Invested in Subordinated Debentures by Trust					$ 6,186,000
Plumas Statutory Trust I [Member] | Subordinated Debt [Member]
Debt Instrument, Interest Rate, Effective Percentage	5.35%
Plumas Statutory Trust I [Member] | Subordinated Debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	3.40%
Plumas Statutory Trust II [Member]
Capital	$ 179,000
Trust Preferred Securities Issued, Number				4,000
Trust Preferred Securities, Liquidation Amount per Preferred Security				$ 1,000
Proceeds from Issuance of Trust Preferred Securities				$ 4,000,000
Amount Invested in Subordinated Debentures by Trust				$ 4,124,000
Debt Instrument, Period for Deferral of Distribution Payment	5 years
Plumas Statutory Trust II [Member] | Subordinated Debt [Member]
Debt Instrument, Interest Rate, Effective Percentage	3.37%
Debt Instrument, Period after Issuance for Start of Redemption	5 years
Plumas Statutory Trust II [Member] | Subordinated Debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.48%