Note 5 - Financial Instruments Measured at Fair Value (Tables)
|
9 Months Ended |
Sep. 26, 2026 |
|---|
| Notes Tables |
|
| Unrealized Gain (Loss) on Investments [Table Text Block] |
| |
|
September 26, 2026
|
|
| |
|
|
|
|
|
Gross
|
|
|
Gross
|
|
|
Estimated
|
|
| |
|
Amortized
|
|
|
Unrealized
|
|
|
Unrealized
|
|
|
Fair
|
|
| |
|
Cost
|
|
|
Gains
|
|
|
Losses (1)
|
|
|
Value
|
|
|
Corporate debt securities (2)
|
|
$ |
118,318 |
|
|
$ |
4 |
|
|
$ |
544 |
|
|
$ |
117,778 |
|
|
Bank certificates of deposit
|
|
|
70,100 |
|
|
|
1 |
|
|
|
94 |
|
|
|
70,007 |
|
|
U.S. treasury securities
|
|
|
31,650 |
|
|
|
- |
|
|
|
257 |
|
|
|
31,393 |
|
|
Asset-backed securities
|
|
|
15,809 |
|
|
|
- |
|
|
|
50 |
|
|
|
15,759 |
|
|
Foreign government security
|
|
|
708 |
|
|
|
- |
|
|
|
- |
|
|
|
708 |
|
| |
|
$ |
236,585 |
|
|
$ |
5 |
|
|
$ |
945 |
|
|
$ |
235,645 |
|
| |
|
|
|
|
|
December 27, 2025
|
|
| |
|
|
|
|
|
Gross
|
|
|
Gross
|
|
|
Estimated
|
|
| |
|
Amortized
|
|
|
Unrealized
|
|
|
Unrealized
|
|
|
Fair
|
|
| |
|
Cost
|
|
|
Gains
|
|
|
Losses (1)
|
|
|
Value
|
|
|
Corporate debt securities (2)
|
|
$ |
150,314 |
|
|
$ |
60 |
|
|
$ |
13 |
|
|
$ |
150,361 |
|
|
Bank certificates of deposit
|
|
|
58,130 |
|
|
|
26 |
|
|
|
- |
|
|
|
58,156 |
|
|
U.S. treasury securities
|
|
|
37,584 |
|
|
|
68 |
|
|
|
- |
|
|
|
37,652 |
|
|
Asset-backed securities
|
|
|
10,038 |
|
|
|
18 |
|
|
|
- |
|
|
|
10,056 |
|
|
Foreign government security
|
|
|
703 |
|
|
|
- |
|
|
|
- |
|
|
|
703 |
|
| |
|
$ |
256,769 |
|
|
$ |
172 |
|
|
$ |
13 |
|
|
$ |
256,928 |
|
|
| Investments Classified by Contractual Maturity Date [Table Text Block] |
| |
|
September 26, 2026
|
|
|
December 27, 2025
|
|
| |
|
Amortized
|
|
|
Estimated
|
|
|
Amortized
|
|
|
Estimated
|
|
| |
|
Cost
|
|
|
Fair Value
|
|
|
Cost
|
|
|
Fair Value
|
|
|
Due in one year or less
|
|
$ |
162,055 |
|
|
$ |
161,769 |
|
|
$ |
200,379 |
|
|
$ |
200,436 |
|
|
Due after one year through five years
|
|
|
74,530 |
|
|
|
73,876 |
|
|
|
56,390 |
|
|
|
56,492 |
|
| |
|
$ |
236,585 |
|
|
$ |
235,645 |
|
|
$ |
256,769 |
|
|
$ |
256,928 |
|
|
| Fair Value, Assets Measured on Recurring Basis [Table Text Block] |
| |
|
Fair value measurements at September 26, 2026 using:
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
Total Estimated
|
|
| |
|
Level 1
|
|
|
Level 2
|
|
|
Level 3
|
|
|
Fair Value
|
|
|
Cash
|
|
$ |
136,566 |
|
|
$ |
- |
|
|
$ |
- |
|
|
$ |
136,566 |
|
|
Corporate debt securities
|
|
|
- |
|
|
|
138,091 |
|
|
|
- |
|
|
|
138,091 |
|
|
Money market funds
|
|
|
- |
|
|
|
115,424 |
|
|
|
- |
|
|
|
115,424 |
|
|
Bank certificates of deposit
|
|
|
- |
|
|
|
70,007 |
|
|
|
- |
|
|
|
70,007 |
|
|
U.S. treasury securities
|
|
|
- |
|
|
|
31,393 |
|
|
|
- |
|
|
|
31,393 |
|
|
Asset-backed securities
|
|
|
- |
|
|
|
15,759 |
|
|
|
- |
|
|
|
15,759 |
|
|
Foreign government security
|
|
|
- |
|
|
|
708 |
|
|
|
- |
|
|
|
708 |
|
| |
|
$ |
136,566 |
|
|
$ |
371,382 |
|
|
$ |
- |
|
|
$ |
507,948 |
|
| |
|
Fair value measurements at December 27, 2025 using:
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
Total Estimated
|
|
| |
|
Level 1
|
|
|
Level 2
|
|
|
Level 3
|
|
|
Fair Value
|
|
|
Cash
|
|
$ |
142,091 |
|
|
$ |
- |
|
|
$ |
- |
|
|
$ |
142,091 |
|
|
Corporate debt securities
|
|
|
- |
|
|
|
183,611 |
|
|
|
- |
|
|
|
183,611 |
|
|
Bank certificates of deposit
|
|
|
- |
|
|
|
58,156 |
|
|
|
- |
|
|
|
58,156 |
|
|
Money market funds
|
|
|
- |
|
|
|
51,712 |
|
|
|
- |
|
|
|
51,712 |
|
|
U.S. treasury securities
|
|
|
- |
|
|
|
37,652 |
|
|
|
- |
|
|
|
37,652 |
|
|
Asset-backed securities
|
|
|
- |
|
|
|
10,056 |
|
|
|
- |
|
|
|
10,056 |
|
|
Foreign government security
|
|
|
- |
|
|
|
703 |
|
|
|
- |
|
|
|
703 |
|
| |
|
$ |
142,091 |
|
|
$ |
341,890 |
|
|
$ |
- |
|
|
$ |
483,981 |
|
|