Note 10 - Acquisition - Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019	Dec. 31, 2019	Mar. 31, 2020
Liabilities assumed:
Goodwill		$ 11,671	$ 11,671
Merchants Holding Company [Member]
Consideration paid:
Cash and fed funds sold		12,425
Investment securities		107,931
Loans, gross		87,570
Allowance for loan and lease losses		(1,286)
Interest receivable		688
Premises and equipment, net		378
Deferred tax assets, net		1,374
Federal Home Loan Bank of San Francisco stock		1,454
Life insurance		755
Other assets		371
Core deposit intangible
Total assets acquired		211,660
Liabilities assumed:
Demand, money market and savings		152,213
Certificates of deposit		38,003
Total deposits		190,216
Other liabilities		916
Total liabilities assumed		191,132
Net identifiable assets acquired over liabilities assumed		20,528
Merchants Holding Company [Member]
Consideration paid:
Cash	$ 15,300	15,300
Stock 1,834,142 shares at $10.69 per share		19,607
Total consideration		34,907
Cash and fed funds sold		12,425
Investment securities		107,380
Investment securities, adjustment		(551)
Loans, gross		85,278
Loans, gross, adjustment		(2,292)
Allowance for loan and lease losses
Allowance for loan and lease losses, adjustment		1,286
Interest receivable		688
Premises and equipment, net		2,234
Premises and equipment, net, adjustment		1,856
Deferred tax assets, net		22
Deferred tax assets, net, adjustment		(1,352)
Federal Home Loan Bank of San Francisco stock		1,454
Life insurance		755
Other assets		466
Other assets, adjustment		95
Core deposit intangible		4,353
Core deposit intangible, adjustment		4,353
Total assets acquired	211,700	215,055
Total assets acquired, adjustment		3,395
Liabilities assumed:
Demand, money market and savings		152,213
Certificates of deposit		38,003
Total deposits		190,216
Other liabilities		938
Other liabilities, adjustment		22
Total liabilities assumed		191,154
Total liabilities assumed, adjustment		22
Net identifiable assets acquired over liabilities assumed		23,901
Net identifiable assets acquired over liabilities assumed, adjustment		3,373
Goodwill	$ 11,000	$ 11,006