Amortized Cost and Fair Value of Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Sep. 28, 2024	Dec. 30, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 151,390	$ 158,143
Gross Unrealized Gains	1,019	281
Gross Unrealized Losses	3,550	6,663
Fair Value	148,859	151,761
Money market investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14,998	16,832
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	14,998	16,832
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,535	16,543
Gross Unrealized Gains	21	0
Gross Unrealized Losses	1,563	2,236
Fair Value	15,993	14,307
Corporate bonds, commercial paper and direct obligations of government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	118,857	118,481
Gross Unrealized Gains	998	279
Gross Unrealized Losses	1,987	4,384
Fair Value	$ 117,868	114,376
U.S. Treasury obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		6,287
Gross Unrealized Gains		2
Gross Unrealized Losses		43
Fair Value		$ 6,246