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Note 6 - Other Assets and Other Liabilities (Details Textual) $ / shares in Units, shares in Thousands, $ in Thousands			3 Months Ended		9 Months Ended
	Jun. 29, 2022	Dec. 29, 2021	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Share Price (in dollars per share) \| $ / shares			$ 177.65		$ 177.65
LIHTC Investments			$ 35,852		$ 35,852		$ 37,145
Qualified Affordable Housing Project Investments, Commitment			$ 25,017		$ 25,017		26,485
Lessee, Operating Lease, Term of Contract (Year)			5 years		5 years
Lessee, Operating Lease, Renewal Term (Year)			5 years		5 years
Operating Lease, Liability, Total			$ 16,576		$ 16,576		17,980
Operating Lease, Right-of-Use Asset			$ 16,576		$ 16,576		$ 17,980
Operating Lease, Weighted Average Remaining Lease Term (Year)			3 years 9 months 18 days		3 years 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent			1.79%		1.79%
Operating Lease, Cost			$ 1,664	$ 1,637	$ 4,934	$ 4,949
Contingent Commitment, Remainder of Fiscal Year [Member]
Qualified Affordable Housing Project Investments, Commitment			2,519		2,519
Contingent Commitment, Year 1 [Member]
Qualified Affordable Housing Project Investments, Commitment			12,200		12,200
Contingent Commitment, Year 2 [Member]
Qualified Affordable Housing Project Investments, Commitment			9,169		9,169
Contingent Commitment, Year 3 [Member]
Qualified Affordable Housing Project Investments, Commitment			244		244
Contingent Commitment, Year 4 [Member]
Qualified Affordable Housing Project Investments, Commitment			128		128
Contingent Commitment, Year 5 [Member]
Qualified Affordable Housing Project Investments, Commitment			207		207
Contingent Commitment, Year 6 or Thereafter [Member]
Qualified Affordable Housing Project Investments, Commitment			$ 550		$ 550
VISA Class B Common Stock [Member]
Investment Owned, Balance, Shares (in shares) \| shares			211		211
Conversion Rate of Class B Common Stock into Class A Common Stock	1.6059	1.6181
VISA Class B Common Stock [Member] \| Reported Value Measurement [Member]
Investment Owned, at Fair Value			$ 0		$ 0