Consolidated Statement of Equity (Deficit) - USD ($) $ in Millions	Total	Common Stock [Member]	Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]	Total Hexion Inc. Deficit [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2015	$ (2,477)	$ 1	$ (526)	$ 296	$ (15)	$ (2,692)	$ (2,476)	$ (1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(38)	0	0	0	0	(38)	(38)
Net loss	(38)
Net Income (Loss) Attributable to Noncontrolling Interest	0							0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		0	0	0		0
Other comprehensive loss	(24)				(24)		(24)	0
Balance at Dec. 31, 2016	(2,539)	1	(526)	296	(39)	(2,730)	(2,538)	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(234)	0	0	0	0	(234)	(234)
Net loss	(234)
Net Income (Loss) Attributable to Noncontrolling Interest	0							0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		0	0	0	31	0	31	0
Other comprehensive loss	31						31
Balance at Dec. 31, 2017	(2,742)	1	(526)	296	(8)	(2,964)	(2,741)	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(162)	0	0	0	0	(162)	(162)
Net loss	(163)
Net Income (Loss) Attributable to Noncontrolling Interest	(1)							(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		0	0	0		0
Other comprehensive loss	(10)				(10)		(10)	0
Cumulative Effect of New Accounting Principle in Period of Adoption	1	0	0	0	0	1	1	0
Balance at Dec. 31, 2018	$ (2,914)	$ 1	$ (526)	$ 296	$ 18	$ (3,125)	$ (2,912)	$ (2)