Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2021	Mar. 04, 2022	Jun. 30, 2021
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 29, 2021
Document Transition Report	false
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
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	LOCO
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Emerging Growth Company	false
Small Business Entity	false
ICFR Auditor Attestation Flag	true
Shell Company	false
Entity Common Stock, Shares Outstanding		36,743,863
Entity Public Float			$ 352
Auditor Name	BDO USA, LLP
Auditor Firm ID	243
Auditor Location	Costa Mesa, California
Current Fiscal Year End Date	--12-29
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0001606366
Amendment Flag	false