Commitments and Contingencies - Additional Information (Details)	12 Months Ended
	Dec. 25, 2019 USD ($) lease agreement lawsuit
Other Commitments [Line Items]
Number of lawsuits consolidated | lawsuit	2
Officers
Other Commitments [Line Items]
Number of at-will employment agreements | agreement	4
Property Lease Guarantee
Other Commitments [Line Items]
Number of leases assigned to franchisees | lease	5
Contingent lease obligations, maximum exposure	$ 2,000,000
Contingent lease obligations, maximum exposure, if discounted at estimated pre-tax cost of debt	1,700,000
Chicken Acquisition Corp
Other Commitments [Line Items]
Purchase commitments, estimated obligations	25,200,000
Impact Damages
Other Commitments [Line Items]
Value of damages awarded	4,356,600
Lost Opportunity Damages
Other Commitments [Line Items]
Value of damages awarded	4,481,206
Total Damages
Other Commitments [Line Items]
Value of damages awarded	8,837,806
Elliott Olvera, et al v. El Pollo Loco, Inc., et al
Other Commitments [Line Items]
Accrual associated with loss contingencies	16,300,000.0
Daniel Turocy, et al. and Ron Huston et al v. El Pollo Loco Holdings, Inc., et al
Other Commitments [Line Items]
Accrual associated with loss contingencies	20,000,000
Janice P. Handlers-Bryman and Michael D. Bryman v. El Pollo Loco, Inc
Other Commitments [Line Items]
Accrual associated with loss contingencies	$ 0