Document and Entity Information - USD ($)	12 Months Ended
	Jan. 03, 2017	Mar. 10, 2017	Jun. 14, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 03, 2017
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Trading Symbol	TACO
Entity Registrant Name	Del Taco Restaurants, Inc.
Entity Central Index Key	0001585583
Current Fiscal Year End Date	--01-03
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		38,731,404
Entity Public Float			$ 278,000,961