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Stockholders’ Equity and Stock-Based Compensation - Restricted Stock Unit Activity (Details) - Equity Incentive Plan - $ / shares	9 Months Ended	12 Months Ended
	Sep. 25, 2021	Dec. 29, 2018
Units
Awards granted (in shares)		318,100
Restricted Stock Units
Units
Beginning balance (in shares)	2,840,922
Awards granted (in shares)	1,030,085
Awards vested (in shares)	(1,457,554)
Awards canceled (in shares)	(38,128)
Ending balance (in shares)	2,375,325
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 19.80
Awards granted (in dollars per share)	36.09
Awards vested (in dollars per share)	16.95
Awards canceled (in dollars per share)	23.82
Ending balance (in dollars per share)	$ 28.55

X

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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