Note 5 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details) - USD ($) $ in Thousands		Jun. 28, 2025	Dec. 28, 2024
Amortized cost		$ 44,953	$ 55,666
Gross unrealized gains		36	62
Gross unrealized losses	[1]	14	43
Short term investment		44,975	55,685
Corporate Debt Securities [Member]
Amortized cost	[2]	21,920	32,040
Gross unrealized gains	[2]	15	37
Gross unrealized losses	[1]	8	25
Short term investment	[2]	21,927	32,052
US Treasury Securities [Member]
Amortized cost		7,182	11,964
Gross unrealized gains		16	12
Gross unrealized losses	[1]	4	15
Short term investment		7,194	11,961
Certificates of Deposit [Member]
Amortized cost		11,590	6,971
Gross unrealized gains		3	4
Gross unrealized losses	[1]	1	3
Short term investment		11,592	6,972
Asset-Backed Securities [Member]
Amortized cost		3,201	3,647
Gross unrealized gains		1	6
Gross unrealized losses	[1]	1	0
Short term investment		3,201	3,653
Debt Security, Government, Non-US [Member]
Amortized cost		730	714
Gross unrealized gains		0	0
Gross unrealized losses	[1]	0	0
Short term investment		730	714
US States and Political Subdivisions Debt Securities [Member]
Amortized cost		330	330
Gross unrealized gains		1	3
Gross unrealized losses	[1]	0	0
Short term investment		$ 331	$ 333

[1] As of June 28, 2025, the cost and fair value of investments with loss positions were both approximately $16.6 million. As of December 28, 2024, the cost and fair value of investments with loss positions was approximately $20.5 million and $20.4 million, respectively. We evaluated the nature of these investments, credit worthiness of the issuer and the duration of these impairments to determine if a credit loss exists. We have the ability and intent to hold these investments to maturity.

[2] Corporate debt securities include investments in financial and other corporate institutions. No single issuer represents a significant portion of the total corporate debt securities portfolio.