Components of Interest Expense from Convertible Senior Notes (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 28, 2020	Dec. 30, 2019
Debt Disclosure [Abstract]
Contractual coupon interest	$ 4,180	$ 4,374
Amortization of debt discount	9,926	9,751
Amortization of debt issuance costs	$ 995	$ 977

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Balance Type:	debit
Period Type:	duration