DESCRIPTION OF BUSINESS - Additional Information (Details)	12 Months Ended
	Dec. 28, 2022 restaurant segment
Debt Instrument [Line Items]
Number of operating segments | segment	1
El Pollo Loco Holdings, Inc | Trimaran Pollo Partners, LLC
Debt Instrument [Line Items]
Noncontrolling ownership percentage	30.30%
El Pollo Loco Holdings, Inc | FS Equity Partners V, L.P
Debt Instrument [Line Items]
Noncontrolling ownership percentage	14.80%
El Pollo Loco Holdings, Inc | FS Affiliates V, L.P
Debt Instrument [Line Items]
Noncontrolling ownership percentage	0.20%
Philippines
Debt Instrument [Line Items]
Number of restaurants	5
Company-operated
Debt Instrument [Line Items]
Number of restaurants	188
Company-operated | Greater Los Angeles area market
Debt Instrument [Line Items]
Number of restaurants	138
Franchised
Debt Instrument [Line Items]
Number of restaurants	302
Franchised | Greater Los Angeles area market
Debt Instrument [Line Items]
Number of restaurants	141