Note 6 - Employee Benefit Plans - Weighted-average Assumptions Used to Value Share-based Awards Granted (Details) - Employee Stock Purchase Plan [Member] - $ / shares	12 Months Ended
	Dec. 28, 2024	Dec. 30, 2023	Dec. 31, 2022
Expected volatility	35.50%	36.30%	45.60%
Risk-free interest rate	5.30%	4.50%	1.20%
Expected term (years) (Year)	6 months	6 months	6 months
Weighted-average grant date fair value per share (in dollars per share)	$ 7.49	$ 8.54	$ 8.79