SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2023	Dec. 28, 2022	Dec. 29, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Property and equipment, net	$ 84,027	$ 78,644
Impairment of property and equipment	$ 1,500	400	$ 300
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]	Restructuring Costs and Asset Impairment Charges
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Property and equipment, net	$ 0	0	0
Right-of-Use Assets, Net	244	327	411
Impairment of property and equipment	1,497	442	304
Impairment Losses of Right-of-Use Assets	39	39	407
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Property and equipment, net	0	0	0
Right-of-Use Assets, Net	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Property and equipment, net	0	0	0
Right-of-Use Assets, Net	0	0
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Property and equipment, net	0	0	0
Right-of-Use Assets, Net	$ 244	$ 327	$ 411