Earnings Per Unit (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 24, 2022	Sep. 30, 2023	Sep. 24, 2022
Class A Units [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income attributable to USPB available to unitholders (numerator)	$ 1,495	$ 4,312	$ 3,691	$ 15,489
Weighted average outstanding units (denominator)	735,385	735,385	735,385	735,385
Per unit amount	2.03	5.86	5.02	21.06
Class B Units [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income attributable to USPB available to unitholders (numerator)	$ 13,459	$ 38,812	$ 33,214	$ 139,396
Weighted average outstanding units (denominator)	755,385	755,385	755,385	755,385
Per unit amount	17.82	51.38	43.97	184.54