Document and Entity Information	3 Months Ended
	Nov. 30, 2011	Jan. 04, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	COMMERCIAL METALS CO
Entity Central Index Key	0000022444
Document Type	10-Q
Document Period End Date	Nov. 30, 2011
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--08-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		115,592,724