Note 10 - Junior Subordinated Deferrable Interest Debentures (Details Textual) - USD ($)		12 Months Ended
	Dec. 31, 2002	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2005	Dec. 31, 2002
Capital		$ 83,753,000	$ 71,878,000
Interest Expense, Junior Subordinated Debentures		510,000	$ 401,000	$ 348,000
Plumas Statutory Trust I [Member]
Capital		$ 338,000
Trust Preferred Securities Issued, Number						6,000
Trust Preferred Securities, Liquidation Amount per Preferred Security	$ 1,000					$ 1,000
Proceeds from Issuance of Trust Preferred Securities	$ 6,000,000
Amount Invested in Subordinated Debentures by Trust	$ 6,186,000					$ 6,186,000
Plumas Statutory Trust I [Member] | Subordinated Debt [Member]
Debt Instrument, Interest Rate, Effective Percentage		6.22%
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		$ 174,000
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		4.27%
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%