Document And Entity Information	12 Months Ended
	Dec. 31, 2014	Mar. 30, 2015
Document And Entity Information
Entity Registrant Name	AmREIT Monthly Income & Growth Fund III Ltd
Entity Central Index Key	0001330466
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2014
Document Type	10-K
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Smaller Reporting Company
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014
Entity Common Stock, Shares Outstanding		2,833