Note 2 - Summary of Significant Accounting Policies (Details Textual) xbrli-pure in Thousands	Mar. 31, 2019 USD ($)	Jan. 01, 2019 USD ($)
Number of Major Customers	0
Operating Lease, Liability, Total	$ 478,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset		$ 565,000
Operating Lease, Liability, Total		$ 565,000
Plumas Statutory Trust 1 [Member] | Accrued Interest Receivable and Other Assets [Member]
Equity Method Investments	341,000
Plumas Statutory Trust II [Member] | Accrued Interest Receivable and Other Assets [Member]
Equity Method Investments	$ 175,000