Document And Entity Information	3 Months Ended
	Jun. 30, 2016 shares
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Entity Registrant Name	BOSTON CAPITAL TAX CREDIT FUND III L P
Entity Central Index Key	0000879555
Current Fiscal Year End Date	--03-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding	0