Convertible Preferred Stock - Summary of Convertible Preferred Stock (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 25, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Shares Authorized	135,936,731	135,936,731
Shares Issued and Outstanding	114,686,731	114,686,731
Aggregate Liquidation Amount	$ 100,187,000	$ 100,187,000
Proceeds from Issuance of Redeemable Convertible Preferred Stock	99,414,000	99,414,000
Net Carrying Value	$ 86,706,000	$ 86,706,000
Series A
Temporary Equity [Line Items]
Shares Authorized	17,000,000	17,000,000
Shares Issued and Outstanding	17,000,000	17,000,000
Per Share Liquidation Preference	$ 1.00	$ 1.00
Aggregate Liquidation Amount	$ 17,000,000	$ 17,000,000
Proceeds from Issuance of Redeemable Convertible Preferred Stock	16,982,000	16,982,000
Net Carrying Value	$ 16,982,000	$ 16,982,000
Series B
Temporary Equity [Line Items]
Shares Authorized	25,186,738	25,186,738
Shares Issued and Outstanding	25,186,738	25,186,738
Per Share Liquidation Preference	$ 1.00	$ 1.00
Aggregate Liquidation Amount	$ 25,187,000	$ 25,187,000
Proceeds from Issuance of Redeemable Convertible Preferred Stock	24,943,000	24,943,000
Net Carrying Value	$ 12,235,000	$ 12,235,000
Series B-1
Temporary Equity [Line Items]
Shares Authorized	93,749,993	93,749,993
Shares Issued and Outstanding	72,499,993	72,499,993
Per Share Liquidation Preference	$ 0.80	$ 0.80
Aggregate Liquidation Amount	$ 58,000,000	$ 58,000,000
Proceeds from Issuance of Redeemable Convertible Preferred Stock	57,489,000	57,489,000
Net Carrying Value	$ 57,489,000	$ 57,489,000