Note 5 - Financial Instruments Measured at Fair Value (Tables)
|
6 Months Ended |
Jun. 25, 2022 |
Notes Tables |
|
Unrealized Gain (Loss) on Investments [Table Text Block] |
|
|
June 25, 2022 |
|
|
|
|
|
|
|
Gross |
|
|
Gross |
|
|
Estimated |
|
|
|
Amortized |
|
|
Unrealized |
|
|
Unrealized |
|
|
Fair |
|
|
|
Cost |
|
|
Gains |
|
|
Losses (1) |
|
|
Value |
|
Corporate debt securities (2) |
|
$ |
63,577 |
|
|
$ |
3 |
|
|
$ |
365 |
|
|
$ |
63,215 |
|
U.S. treasury securities |
|
|
8,722 |
|
|
|
- |
|
|
|
105 |
|
|
|
8,617 |
|
Bank certificates of deposit |
|
|
10,750 |
|
|
|
1 |
|
|
|
32 |
|
|
|
10,719 |
|
Foreign government security |
|
|
841 |
|
|
|
- |
|
|
|
- |
|
|
|
841 |
|
Asset-backed securities |
|
|
4,138 |
|
|
|
- |
|
|
|
35 |
|
|
|
4,103 |
|
|
|
$ |
88,028 |
|
|
$ |
4 |
|
|
$ |
537 |
|
|
$ |
87,495 |
|
|
|
December 25, 2021 |
|
|
|
|
|
|
|
Gross |
|
|
Gross |
|
|
Estimated |
|
|
|
Amortized |
|
|
Unrealized |
|
|
Unrealized |
|
|
Fair |
|
|
|
Cost |
|
|
Gains |
|
|
Losses (1) |
|
|
Value |
|
Corporate debt securities (2) |
|
$ |
84,060 |
|
|
$ |
2 |
|
|
$ |
31 |
|
|
$ |
84,031 |
|
U.S. treasury securities |
|
|
3,953 |
|
|
|
- |
|
|
|
5 |
|
|
|
3,948 |
|
Bank certificates of deposit |
|
|
800 |
|
|
|
- |
|
|
|
- |
|
|
|
800 |
|
Foreign government security |
|
|
925 |
|
|
|
- |
|
|
|
- |
|
|
|
925 |
|
|
|
$ |
89,738 |
|
|
$ |
2 |
|
|
$ |
36 |
|
|
$ |
89,704 |
|
|
Investments Classified by Contractual Maturity Date [Table Text Block] |
|
|
June 25, 2022 |
|
|
December 25, 2021 |
|
|
|
Amortized |
|
|
Estimated |
|
|
Amortized |
|
|
Estimated |
|
|
|
Cost |
|
|
Fair Value |
|
|
Cost |
|
|
Fair Value |
|
Due in one year or less |
|
$ |
71,917 |
|
|
$ |
71,636 |
|
|
$ |
83,429 |
|
|
$ |
83,408 |
|
Due after one year through three years |
|
|
16,111 |
|
|
|
15,859 |
|
|
|
6,309 |
|
|
|
6,296 |
|
|
|
$ |
88,028 |
|
|
$ |
87,495 |
|
|
$ |
89,738 |
|
|
$ |
89,704 |
|
|
Fair Value, Assets Measured on Recurring Basis [Table Text Block] |
|
|
Fair value measurements at June 25, 2022 using: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total estimated |
|
|
|
Level 1 |
|
|
Level 2 |
|
|
Level 3 |
|
|
fair value |
|
Cash |
|
$ |
221,695 |
|
|
$ |
- |
|
|
$ |
- |
|
|
$ |
221,695 |
|
U.S. treasury securities |
|
|
- |
|
|
|
8,618 |
|
|
|
- |
|
|
|
8,618 |
|
Corporate debt securities |
|
|
- |
|
|
|
70,207 |
|
|
|
- |
|
|
|
70,207 |
|
Asset-backed securities |
|
|
- |
|
|
|
4,103 |
|
|
|
- |
|
|
|
4,103 |
|
Money market funds |
|
|
- |
|
|
|
51,898 |
|
|
|
- |
|
|
|
51,898 |
|
Bank certificates of deposit |
|
|
- |
|
|
|
10,719 |
|
|
|
- |
|
|
|
10,719 |
|
Foreign government security |
|
|
- |
|
|
|
841 |
|
|
|
- |
|
|
|
841 |
|
|
|
$ |
221,695 |
|
|
$ |
146,386 |
|
|
$ |
- |
|
|
$ |
368,081 |
|
|
|
Fair value measurements at December 25, 2021 using: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total estimated |
|
|
|
Level 1 |
|
|
Level 2 |
|
|
Level 3 |
|
|
fair value |
|
Cash |
|
$ |
195,297 |
|
|
$ |
- |
|
|
$ |
- |
|
|
$ |
195,297 |
|
Corporate debt securities |
|
|
- |
|
|
|
86,535 |
|
|
|
- |
|
|
|
86,535 |
|
U.S. treasury securities |
|
|
- |
|
|
|
3,948 |
|
|
|
- |
|
|
|
3,948 |
|
Money market funds |
|
|
- |
|
|
|
92,400 |
|
|
|
- |
|
|
|
92,400 |
|
Bank certificates of deposit |
|
|
- |
|
|
|
800 |
|
|
|
- |
|
|
|
800 |
|
Foreign government security |
|
|
- |
|
|
|
925 |
|
|
|
- |
|
|
|
925 |
|
|
|
$ |
195,297 |
|
|
$ |
184,608 |
|
|
$ |
- |
|
|
$ |
379,905 |
|
|