Note 5 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details) - USD ($) $ in Thousands		Mar. 28, 2026	Dec. 27, 2025
Amortized cost		$ 278,117	$ 256,769
Gross unrealized gains		40	172
Gross unrealized losses	[1]	398	13
Short term investment		277,759	256,928
Corporate Debt Securities [Member]
Amortized cost	[2]	147,366	150,314
Gross unrealized gains	[2]	21	60
Gross unrealized losses	[1]	206	13
Short term investment	[2]	147,181	150,361
Certificates of Deposit [Member]
Amortized cost		73,260	58,130
Gross unrealized gains		6	26
Gross unrealized losses	[1]	70	0
Short term investment		73,196	58,156
US Treasury Securities [Member]
Amortized cost		42,121	37,584
Gross unrealized gains		11	68
Gross unrealized losses	[1]	99	0
Short term investment		42,033	37,652
Asset-Backed Securities [Member]
Amortized cost		14,689	10,038
Gross unrealized gains		2	18
Gross unrealized losses	[1]	23	0
Short term investment		14,668	10,056
Debt Security, Government, Non-US [Member]
Amortized cost		681	703
Gross unrealized gains		0	0
Gross unrealized losses	[1]	0	0
Short term investment		$ 681	$ 703

[1] As of March 28, 2026, the cost and fair value of investments with loss positions were approximately $211.0 million and $210.6 million, respectively. As of December 27, 2025, the cost and fair value of investments with loss positions were both approximately $58.3 million. We evaluated the nature of these investments, credit worthiness of the issuer and the duration of these impairments to determine if a credit-related decline in fair value had occurred and concluded that these losses were temporary and 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.