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Equity-based compensation - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 01, 2023	Jul. 02, 2022	Jul. 01, 2023	Jul. 02, 2022	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized compensation expense, options	$ 8,485,000		$ 8,485,000
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized compensation expense, RSUs	$ 9,010,000		$ 9,010,000
Compensation expense net yet amortized, period for recognition			2 years 4 months 20 days
RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense net yet amortized, period for recognition			6 years 11 months 19 days
Expiration period			10 years
Weighted-average fair value of stock options granted (in dollars per share)			$ 0.49
Stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year		1 year
Stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years		4 years
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to be awarded (in shares)	1,036,979		1,036,979
Equity compensation	$ 65,000	$ 94,000	$ 193,000	$ 252,000
Number of shares issued (in shares)	144,851	53,826	366,927	102,819
2021 and 2023 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity compensation	$ (2,797,000)	$ 4,522,000	$ (1,079,000)	$ 9,253,000
Income tax benefit	$ 0	$ 1,065,000	$ 0	$ 2,290,000
Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock closing price, (in dollars per share)					$ 2.89
Common Class A \| 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be awarded (in shares)	14,781,895		14,781,895
Number of shares available to be awarded (in shares)	5,912,880		5,912,880
Common Class A \| 2023 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be awarded (in shares)	600,000		600,000
Number of shares available to be awarded (in shares)	32,700		32,700