Cash, cash equivalents and short-term investments (Detail) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Fair Value Measurements [Line Items]
Amortized Cost		$ 242,518
Gross Unrealized Gains		8
Gross Unrealized Losses		0
Estimated Fair Value		242,526
Cash
Fair Value Measurements [Line Items]
Amortized Cost	$ 138,381	146,083
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	138,381	146,083
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	101,572	51,442
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	101,572	51,442
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	101,572	51,442
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	101,572	51,442
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	239,953	197,525
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 239,953	197,525
U.S. Treasury and agency securities
Fair Value Measurements [Line Items]
Amortized Cost		44,993
Gross Unrealized Gains		8
Gross Unrealized Losses		0
Estimated Fair Value		45,001
Total short-term investments
Fair Value Measurements [Line Items]
Amortized Cost		44,993
Gross Unrealized Gains		8
Gross Unrealized Losses		0
Estimated Fair Value		$ 45,001

Fair Value Measurements [Line Items]

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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