Document and Entity Information	9 Months Ended
	Sep. 30, 2018 shares
Document and Entity Information [Abstract]
Entity Registrant Name	MASCO CORP /DE/
Entity Central Index Key	0000062996
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)	305,498,347