Guarantor Non-Guarantor Subsidiary Financial Information Level 4 (Details) - Consolidating Statement of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 3,797	$ 3,591	$ 3,438
Cost of Goods and Services Sold	3,226	3,088	3,020
Gross profit	571	503	418
Selling, general and administrative expense	295	321	318
Gain (Loss) on Disposition of Business	44	0	(240)
Asset Impairment Charges	28	13	0
Business realignment costs	29	52	55
Other operating expense (income), net	36	17	13
Operating income	227	100	272
Loss (gain) on extinguishment of debt	0	3	(48)
Other non-operating (income) expense, net	(12)	(12)	21
Loss before earnings from unconsolidated entities	(126)	(220)	(11)
Income tax (benefit) expense	40	18	38
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(166)	(238)	(49)
Earnings from unconsolidated entities, net of taxes	3	4	11
Net loss	(163)	(234)	(38)
Net Income (Loss) Attributable to Noncontrolling Interest	1	0	0
Net loss attributable to Hexion Inc.	(162)	(234)	(38)
Comprehensive income (loss)	(172)	(203)	(62)
Momentive Specialty Chemicals Inc. [Member]
Revenues	1,730	1,586	1,449
Cost of Goods and Services Sold	1,452	1,374	1,371
Gross profit	278	212	78
Selling, general and administrative expense	146	148	145
Gain (Loss) on Disposition of Business	(24)		(188)
Asset Impairment Charges	25	13
Business realignment costs	16	24	39
Other operating expense (income), net	13	3	18
Operating income	102	24	64
Interest expense, net	349	315	300
Intercompany interest expense (income)	(83)	(75)	(72)
Loss (gain) on extinguishment of debt		3	(48)
Other non-operating (income) expense, net	40	(79)	12
Loss before earnings from unconsolidated entities	(204)	(140)	(128)
Income tax (benefit) expense	(7)	(7)	(3)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(197)	(133)	(125)
Earnings from unconsolidated entities, net of taxes	35	(101)	88
Net income from continuing operations			(37)
Net loss	(162)	(234)
Net Income (Loss) Attributable to Noncontrolling Interest	0
Net loss attributable to Hexion Inc.	(162)
Comprehensive income (loss)	(172)	(203)	(62)
Combined Subsidiary Guarantors [Member]
Revenues	0	0	0
Cost of Goods and Services Sold	0	0	0
Gross profit	0	0	0
Selling, general and administrative expense	0	0	0
Gain (Loss) on Disposition of Business	0		0
Asset Impairment Charges	0	0
Business realignment costs	0	0	0
Other operating expense (income), net	(1)	(1)	5
Operating income	1	1	(5)
Interest expense, net	0	0	0
Intercompany interest expense (income)	0	0	0
Loss (gain) on extinguishment of debt		0	0
Other non-operating (income) expense, net	0	0	0
Loss before earnings from unconsolidated entities	1	1	(5)
Income tax (benefit) expense	0	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(1)	1	5
Earnings from unconsolidated entities, net of taxes	24	(64)	31
Net income from continuing operations			26
Net loss	25	(63)
Net Income (Loss) Attributable to Noncontrolling Interest	0
Net loss attributable to Hexion Inc.	25
Comprehensive income (loss)	25	(63)	25
Combined Non-Guarantor Subsidiaries [Member]
Revenues	2,261	2,203	2,171
Cost of Goods and Services Sold	1,968	1,912	1,831
Gross profit	293	291	340
Selling, general and administrative expense	149	173	173
Gain (Loss) on Disposition of Business	(20)		(52)
Asset Impairment Charges	3	0
Business realignment costs	13	28	16
Other operating expense (income), net	24	15	(10)
Operating income	124	75	213
Interest expense, net	16	14	10
Intercompany interest expense (income)	83	75	72
Loss (gain) on extinguishment of debt		0	0
Other non-operating (income) expense, net	(52)	67	9
Loss before earnings from unconsolidated entities	77	(81)	122
Income tax (benefit) expense	47	25	41
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(30)	(106)	81
Earnings from unconsolidated entities, net of taxes	3	4	5
Net income from continuing operations			86
Net loss	33	(102)
Net Income (Loss) Attributable to Noncontrolling Interest	(1)
Net loss attributable to Hexion Inc.	34
Comprehensive income (loss)	48	(108)	66
Consolidated [Member]
Revenues	3,797	3,591	3,438
Cost of Goods and Services Sold	3,226	3,088	3,020
Gross profit	571	503	418
Selling, general and administrative expense	295	321	318
Gain (Loss) on Disposition of Business	(44)		(240)
Asset Impairment Charges	28	13
Business realignment costs	29	52	55
Other operating expense (income), net	36	17	13
Operating income	227	100	272
Interest expense, net	365	329	310
Intercompany interest expense (income)	0	0	0
Loss (gain) on extinguishment of debt		3	(48)
Other non-operating (income) expense, net	(12)	(12)	21
Loss before earnings from unconsolidated entities	(126)	(220)	(11)
Income tax (benefit) expense	40	18	38
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(166)	(238)	(49)
Earnings from unconsolidated entities, net of taxes	3	4	11
Net income from continuing operations			(38)
Net loss	(163)	(234)
Net Income (Loss) Attributable to Noncontrolling Interest	1
Net loss attributable to Hexion Inc.	(162)
Comprehensive income (loss)	(172)	(203)	(62)
Consolidation, Eliminations [Member]
Revenues	(194)	(198)	(182)
Cost of Goods and Services Sold	(194)	(198)	(182)
Gross profit	0	0	0
Selling, general and administrative expense	0	0	0
Gain (Loss) on Disposition of Business	0		0
Asset Impairment Charges	0	0
Business realignment costs	0	0	0
Other operating expense (income), net	0	0	0
Operating income	0	0	0
Interest expense, net	0	0	0
Intercompany interest expense (income)	0	0	0
Loss (gain) on extinguishment of debt		0	0
Other non-operating (income) expense, net	0	0	0
Loss before earnings from unconsolidated entities	0	0	0
Income tax (benefit) expense	0	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	0	0	0
Earnings from unconsolidated entities, net of taxes	(59)	165	(113)
Net income from continuing operations			(113)
Net loss	(59)	165
Net Income (Loss) Attributable to Noncontrolling Interest	0
Net loss attributable to Hexion Inc.	(59)
Comprehensive income (loss)	$ (73)	$ 171	$ (91)