Document and Entity Information	9 Months Ended
	Sep. 30, 2015 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Trading Symbol	DTRPIII
Entity Registrant Name	DEL TACO RESTAURANT PROPERTIES III
Entity Central Index Key	0000786360
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	47,261