Note 5 - Premises, Equipment, Other Assets and Other Liabilities (Details Textual) $ / shares in Units, shares in Thousands, $ in Thousands			12 Months Ended
	Dec. 29, 2021	Dec. 28, 2021	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Depreciation, Depletion and Amortization, Nonproduction, Total			$ 2,978	$ 3,683	$ 3,879
FRB Membership, Stock Subscription, Percent of Paid-Up Capital Stock and Surplus Requirement			6.00%
Share Price (in dollars per share) | $ / shares			$ 57.73
LIHTC Investments			$ 37,145	18,335
Qualified Affordable Housing Project Investments, Commitment			$ 26,485	12,202
Lessee, Operating Lease, Term of Contract (Year)			5 years
Lessee, Operating Lease, Renewal Term (Year)			5 years
Operating Lease, Weighted Average Remaining Lease Term (Year)			4 years 2 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent			1.67%
Operating Lease, Right-of-Use Asset			$ 17,980
Occupancy and Equipment Expense [Member]
Operating Lease, Cost			6,581	6,699
Other Liabilities [Member]
Operating Lease, Liability, Total			17,980	$ 18,832
Contingent Commitment, Year 1 [Member]
Qualified Affordable Housing Project Investments, Commitment			6,830
Contingent Commitment, Year 2 [Member]
Qualified Affordable Housing Project Investments, Commitment			11,826
Contingent Commitment, Year 3 [Member]
Qualified Affordable Housing Project Investments, Commitment			6,769
Contingent Commitment, Year 4 [Member]
Qualified Affordable Housing Project Investments, Commitment			241
Contingent Commitment, Year 5 [Member]
Qualified Affordable Housing Project Investments, Commitment			125
Contingent Commitment, Year 6 [Member]
Qualified Affordable Housing Project Investments, Commitment			203
Contingent Commitment, Year 7 or Thereafter [Member]
Qualified Affordable Housing Project Investments, Commitment			$ 491
VISA Class B Common Stock [Member]
Investment Owned, Balance, Shares (in shares) | shares			211
Conversion Rate of Class B Common Stock into Class A Common Stock	1.6181	1.6228
Share Price (in dollars per share) | $ / shares			$ 216.71
VISA Class B Common Stock [Member] | Reported Value Measurement [Member]
Investment Owned, at Fair Value			$ 0