Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 25, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	SG BLOCKS, INC.
Entity Central Index Key	0001023994
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2017
Entity Filer Category	Smaller Reporting Company
Trading Symbol	SGBXQ
Entity Common Stock, Shares Outstanding		163,901