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, 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) income	(234)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	0
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	31				31		31	0
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)
Net (loss) income	(163)	0	0	0	0	(162)	(162)	(1)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	0
Net Income (Loss) Attributable to Noncontrolling Interest	1
Other comprehensive loss	(10)	0	0	0	(10)	0	(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)
Balance at Jul. 01, 2019	(1)	0	0	0	0	0	0	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(89)
Net (loss) income	(88)	0	0	0	0	(89)	(89)	1
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	8	0		0	0	0	8	0
Net Income (Loss) Attributable to Noncontrolling Interest	(1)
Other comprehensive loss	(1)	0	0	0	(1)	0	(1)	0
Balance at Dec. 31, 2019	$ 1,075	$ 0	$ (1,165)	$ 0	$ (1)	$ (89)	$ 1,075	$ 0