Document and Entity Information Document - USD ($)	6 Months Ended
	Dec. 31, 2019	Mar. 01, 2020
Document Information [Line Items]
Entity Registrant Name	Hexion Inc.
Entity Central Index Key	0000013239
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		100
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float	$ 0