Note 6 - Employee Benefit Plans (Details Textual) - USD ($)			12 Months Ended
	Dec. 30, 2023	May 10, 2023	Dec. 30, 2023	Dec. 31, 2022	Dec. 25, 2021
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay			8.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount			$ 2,500,000	$ 2,400,000	$ 2,400,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	$ 100,000		100,000
Deferred Compensation Liability, Current	900,000		900,000	1,100,000
Cash Surrender Value of Life Insurance	1,400,000		$ 1,400,000	$ 1,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0	0	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 0	$ 200,000	$ 8,400,000
Restricted Stock Units (RSUs) [Member] | Vesting Over One Year Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			1 year
Restricted Stock Units (RSUs) [Member] | Vesting Over Two Year Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			2 years
Restricted Stock Units (RSUs) [Member] | Vesting Over Four Year Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			4 years
Equity Based Performance Stock Units Granted in 2020, 2019, 2018, and 2017 [Member] | Vest on the Third Anniversary of Awards Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			100.00%
Unvested Restricted Stock Units [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 27,900,000		$ 27,900,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			2 years 2 months 12 days
Minimum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Shares Available for Issue	0.00%		0.00%
Maximum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Shares Available for Issue	200.00%		200.00%
Employee Stock Purchase Plan [Member]
Employee Stock Purchase Plan, Shares Reserved for Future Issuance (in shares)	3,750,000		3,750,000
Percentage of Fair Value to Determine Price of Common Stock	85.00%		85.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)			146,829	160,855	161,351
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	799,669	600,000	799,669
Share-Based Compensation Arrangement by Share-Based Payment Award, Share Value		$ 12,500
Equity Incentive Plan 2005 [Member]
Percentage of Fair Value to Determine Price of Common Stock	100.00%		100.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	3,509,023	3,200,000	3,509,023
Cash Payout of Performance Awards Limitation Per Year	$ 4,000,000	$ 2,000,000
Equity Incentive Plan 2005 [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Equity Incentive Plan 2005 [Member] | Minimum [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			1 year
Equity Incentive Plan 2005 [Member] | Maximum [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			4 years
Equity Incentive Plan 2005 [Member] | Director [Member]
Annual Limitation on Compensation		$ 750,000
Postretirement Health Coverage [Member]
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)			$ (6,000)	$ 382,000
Defined Benefit Plan, Expected Future Benefit Payment, Year One	100,000		100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	100,000		100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	100,000		100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	100,000		100,000
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years	$ 600,000		600,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)			$ 100,000	$ 100,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.70%		4.70%	4.90%	2.50%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.40%		4.40%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 100,000		$ 100,000
Swiss Plan [Member]
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax	4,200,000		4,200,000	$ 6,800,000
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)			(1,391,000)	6,043,000
Defined Benefit Plan, Expected Future Employee and Employer Contributions, Next Twelve Months	900,000		900,000
Defined Benefit Plan, Expected Future Benefit Payment, Year One	1,200,000		1,200,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	1,100,000		1,100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	1,200,000		1,200,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	1,400,000		1,400,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	1,300,000		1,300,000
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years	$ 7,300,000		7,300,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)			$ 553,000	$ 395,000	$ 1,228,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.50%		1.50%	2.30%
Swiss Plan [Member] | Debt Securities and Cash [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	50.00%		50.00%
Swiss Plan [Member] | Real Estate Investments [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	24.00%		24.00%
Swiss Plan [Member] | Alternative Investments [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	16.00%		16.00%
Swiss Plan [Member] | Defined Benefit Plan, Equity Securities [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	10.00%		10.00%
Pre Age 65 Plan [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	7.90%		7.90%
Defined Benefit Plan, Health Care Cost Trend Rate, Annual Rate of Change	(0.39%)		(0.39%)
Post Age 65 Plan [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	8.70%		8.70%
Defined Benefit Plan, Health Care Cost Trend Rate, Annual Rate of Change	(0.48%)		(0.48%)