Stockholders' Equity - Grants and Exercises Under Option Plans (Details) - USD ($)	12 Months Ended
Dec. 27, 2020	Dec. 29, 2019	Dec. 30, 2018
Share-based Payment Arrangement [Abstract]
Weighted average grant date fair value of options granted (in dollars per share)	$ 0	$ 10.25	$ 7.54
Total intrinsic value of options exercised	$ 1,446,400	$ 8,874,900	$ 40,600

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration