v3.26.1
SEGMENT REPORTING - Schedule of Segment Reporting (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jul. 01, 2026
Jun. 25, 2025
Jul. 01, 2026
Jun. 25, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Revenue from contract with customer $ 417,618 $ 356,466 $ 784,355 $ 677,364  
Less:          
Food and paper costs 116,276 96,621 216,299 182,658  
Labor and related expenses 101,226 88,058 193,943 174,726  
Other operating expenses 63,118 50,768 120,630 99,030  
Occupancy and related expenses 30,151 25,593 58,805 50,224  
General and administrative expenses 48,321 40,671 101,929 81,311  
Depreciation and amortization expense 30,717 26,545 59,837 53,088  
Pre-opening costs 6,638 4,955 13,508 8,173  
Interest expense 553 548 1,101 1,111  
Income tax expense 5,913 6,193 5,768 6,930  
Other income, net 2,602 2,850 5,345 5,821  
NET INCOME 16,882 18,483 16,588 22,996  
TOTAL ASSETS 1,950,280   1,950,280   $ 1,896,209
Interest income 85 49 117 88  
Reportable Segment          
Less:          
TOTAL ASSETS 1,950,280   1,950,280   $ 1,896,209
Reportable Segment | Operating Segments          
Segment Reporting [Line Items]          
Revenue from contract with customer 417,618 356,466 784,355 677,364  
Less:          
Food and paper costs 116,276 96,621 216,299 182,658  
Labor and related expenses 101,226 88,058 193,943 174,726  
Other operating expenses 63,118 50,768 120,630 99,030  
Occupancy and related expenses 30,151 25,593 58,805 50,224  
General and administrative expenses 48,321 40,671 101,929 81,311  
Depreciation and amortization expense 30,717 26,545 59,837 53,088  
Pre-opening costs 6,638 4,955 13,508 8,173  
Impairments, loss on disposal of assets, and Shack closures 425 881 1,292 2,938  
Interest expense 553 548 1,101 1,111  
Income tax expense 5,913 6,193 5,768 6,930  
Other income, net (2,602) (2,850) (5,345) (5,821)  
NET INCOME 16,882 18,483 16,588 22,996  
Reportable Segment | Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment          
Less:          
NET INCOME $ 0 $ 0 $ 0 $ 0