Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2015	Oct. 30, 2015	Mar. 31, 2015
Document and Entity Information
Entity Registrant Name	HEADWATERS INC
Entity Central Index Key	0001003344
Document Type	10-K
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,313,782,947
Entity Common Stock, Shares Outstanding		73,900,098
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY