0001001 - Document - COVER PAGE link:presentationLink link:calculationLink link:definitionLink 1001002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 1002003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 1003004 - Statement - CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 1004005 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' AND MEMBERS' EQUITY (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 1005006 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 2101101 - Disclosure - DESCRIPTION OF BUSINESS link:presentationLink link:calculationLink link:definitionLink 2402401 - Disclosure - DESCRIPTION OF BUSINESS (Details) link:presentationLink link:calculationLink link:definitionLink 2103102 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES link:presentationLink link:calculationLink link:definitionLink 2204201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) link:presentationLink link:calculationLink link:definitionLink 2405402 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) link:presentationLink link:calculationLink link:definitionLink 2106103 - Disclosure - REVENUE RECOGNITION link:presentationLink link:calculationLink link:definitionLink 2307301 - Disclosure - REVENUE RECOGNITION (Tables) link:presentationLink link:calculationLink link:definitionLink 2408403 - Disclosure - REVENUE RECOGNITION (Details) link:presentationLink link:calculationLink link:definitionLink 2109104 - Disclosure - INVENTORY link:presentationLink link:calculationLink link:definitionLink 2310302 - Disclosure - INVENTORY (Tables) link:presentationLink link:calculationLink link:definitionLink 2411404 - Disclosure - INVENTORY (Details) link:presentationLink link:calculationLink link:definitionLink 2112105 - Disclosure - PROPERTY & EQUIPMENT, NET link:presentationLink link:calculationLink link:definitionLink 2313303 - Disclosure - PROPERTY & EQUIPMENT, NET (Tables) link:presentationLink link:calculationLink link:definitionLink 2414405 - Disclosure - PROPERTY & EQUIPMENT, NET (Details) link:presentationLink link:calculationLink link:definitionLink 2115106 - Disclosure - GOODWILL & INTANGIBLE ASSETS link:presentationLink link:calculationLink link:definitionLink 2316304 - Disclosure - GOODWILL & INTANGIBLE ASSETS (Tables) link:presentationLink link:calculationLink link:definitionLink 2417406 - Disclosure - GOODWILL & INTANGIBLE ASSETS - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2418407 - Disclosure - GOODWILL & INTANGIBLE ASSETS - Summary of Intangible Assets, Net (Details) link:presentationLink link:calculationLink link:definitionLink 2418407 - Disclosure - GOODWILL & INTANGIBLE ASSETS - Summary of Intangible Assets, Net (Details) link:presentationLink link:calculationLink link:definitionLink 2119107 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS link:presentationLink link:calculationLink link:definitionLink 2320305 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables) link:presentationLink link:calculationLink link:definitionLink 2421408 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) link:presentationLink link:calculationLink link:definitionLink 2122108 - Disclosure - DEBT link:presentationLink link:calculationLink link:definitionLink 2323306 - Disclosure - DEBT (Tables) link:presentationLink link:calculationLink link:definitionLink 2424409 - Disclosure - DEBT - Summary of Debt (Details) link:presentationLink link:calculationLink link:definitionLink 2424409 - Disclosure - DEBT - Summary of Debt (Details) link:presentationLink link:calculationLink link:definitionLink 2425410 - Disclosure - DEBT - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2126109 - Disclosure - NON-CONTROLLING INTERESTS link:presentationLink link:calculationLink link:definitionLink 2327307 - Disclosure - NON-CONTROLLING INTERESTS (Tables) link:presentationLink link:calculationLink link:definitionLink 2428411 - Disclosure - NON-CONTROLLING INTERESTS - Schedule of LLC interest Ownership by Portillo's Inc. and Pre-IPO LLC Members (Details) link:presentationLink link:calculationLink link:definitionLink 2429412 - Disclosure - NON-CONTROLLING INTERESTS - Changes in Ownership in Portillo's OpCo on the Company’s Equity (Details) link:presentationLink link:calculationLink link:definitionLink 2130110 - Disclosure - EQUITY-BASED COMPENSATION link:presentationLink link:calculationLink link:definitionLink 2331308 - Disclosure - EQUITY-BASED COMPENSATION (Tables) link:presentationLink link:calculationLink link:definitionLink 2432413 - Disclosure - EQUITY-BASED COMPENSATION - Stock-Based Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 2433414 - Disclosure - EQUITY-BASED COMPENSATION - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2134111 - Disclosure - INCOME TAXES link:presentationLink link:calculationLink link:definitionLink 2435415 - Disclosure - INCOME TAXES - (Details) link:presentationLink link:calculationLink link:definitionLink 2136112 - Disclosure - EARNINGS PER SHARE link:presentationLink link:calculationLink link:definitionLink 2337309 - Disclosure - EARNINGS PER SHARE (Tables) link:presentationLink link:calculationLink link:definitionLink 2438416 - Disclosure - EARNINGS PER SHARE - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2439417 - Disclosure - EARNINGS PER SHARE - Schedule of Basic and Diluted Earnings (Loss) per Share (Details) link:presentationLink link:calculationLink link:definitionLink 2440418 - Disclosure - EARNINGS PER SHARE - Schedule of Units Excluded from Calculation of Diluted Earnings per Share (Details) link:presentationLink link:calculationLink link:definitionLink 2141113 - Disclosure - CONTINGENCIES link:presentationLink link:calculationLink link:definitionLink 2142114 - Disclosure - RELATED PARTY TRANSACTIONS link:presentationLink link:calculationLink link:definitionLink 2343310 - Disclosure - RELATED PARTY TRANSACTIONS (Tables) link:presentationLink link:calculationLink link:definitionLink 2444419 - Disclosure - RELATED PARTY TRANSACTIONS (Details) link:presentationLink link:calculationLink link:definitionLink