| Document and Entity Information | Dec. 08, 2021 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Dec. 8, 2021 |
| Entity File Number | 001-36556 |
| Entity Registrant Name | El Pollo Loco Holdings, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 20-3563182 |
| Entity Address, Address Line One | 3535 Harbor Blvd |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Costa Mesa |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92626 |
| City Area Code | 714 |
| Local Phone Number | 599-5000 |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001606366 |
| Amendment Flag | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | LOCO |
| Security Exchange Name | NASDAQ |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Written Communications | false |
