SUPPLEMENTARY INFORMATION (Sundry Income, Net) (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2020	Jun. 30, 2020	Sep. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplementary Information [Line Items]
Non-operating pension and other postretirement benefit plan net credit				$ 332	$ 103	$ 205
Foreign exchange gains (losses)				(8)	(62)	91
Gain (loss) on divestiture				16	717	(49)
Loss on early extinguishment of debt				(574)	(149)	(102)
Gain (loss) related to litigation settlement				54	544	205
Gain (Loss) on Disposition of Other Assets				105	48	67
Charges related to separation, distribution and tax matters agreements				30	(21)	(144)
Other - net				10	84	113
Sundry income (expense) - net				(35)	1,269	461
Commercial Creditors Litigation
Supplementary Information [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)				0	0	(50)
Dow V. Nova Chemicals Corporation Ethylene Asset Matter [Member] [Member]
Supplementary Information [Line Items]
Gain (loss) related to litigation settlement	$ 552	$ 18	$ 186
Marine and Terminal Operations and Assets
Supplementary Information [Line Items]
Gain (loss) on divestiture					499
Rail Infrastructure Operations and Assets [Member]
Supplementary Information [Line Items]
Gain (loss) on divestiture					233
Nonoperating Income (Expense)
Supplementary Information [Line Items]
Gain (loss) on divestiture				16	(15)	(49)
Charges related to separation, distribution and tax matters agreements				30	(21)	(69)
Nonoperating Income (Expense) | Breast Implant and Other Products Liability Claims
Supplementary Information [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)				0	5	85
Nonoperating Income (Expense) | Dow V. Nova Chemicals Corporation Ethylene Asset Matter [Member] [Member]
Supplementary Information [Line Items]
Gain (loss) related to litigation settlement				0	544	170
Nonoperating Income (Expense) | Luxi Chemical Group Breach of Contract Matter
Supplementary Information [Line Items]
Gain (loss) related to litigation settlement				54	0	0
Nonoperating Income (Expense) | Marine and Terminal Operations and Assets
Supplementary Information [Line Items]
Gain (loss) on divestiture				0	499	0
Nonoperating Income (Expense) | Rail Infrastructure Operations and Assets [Member]
Supplementary Information [Line Items]
Gain (loss) on divestiture				0	233	0
The Dow Chemical Company
Supplementary Information [Line Items]
Non-operating pension and other postretirement benefit plan net credit				332	103	205
Foreign exchange gains (losses)				(13)	(65)	77
Loss on early extinguishment of debt				(574)	(149)	(102)
Gain (Loss) on Disposition of Other Assets				105	48	67
Other - net				3	82	113
Sundry income (expense) - net				(79)	1,274	573
The Dow Chemical Company | Commercial Creditors Litigation
Supplementary Information [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)				0	0	(50)
The Dow Chemical Company | Nonoperating Income (Expense)
Supplementary Information [Line Items]
Gain (loss) on divestiture				16	(15)	2
Charges related to separation, distribution and tax matters agreements				(2)	(11)	6
The Dow Chemical Company | Nonoperating Income (Expense) | Breast Implant and Other Products Liability Claims
Supplementary Information [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)				0	5	85
The Dow Chemical Company | Nonoperating Income (Expense) | Dow V. Nova Chemicals Corporation Ethylene Asset Matter [Member] [Member]
Supplementary Information [Line Items]
Gain (loss) related to litigation settlement				0	544	170
The Dow Chemical Company | Nonoperating Income (Expense) | Luxi Chemical Group Breach of Contract Matter
Supplementary Information [Line Items]
Gain (loss) related to litigation settlement				54	0	0
The Dow Chemical Company | Nonoperating Income (Expense) | Marine and Terminal Operations and Assets
Supplementary Information [Line Items]
Gain (loss) on divestiture				0	499	0
The Dow Chemical Company | Nonoperating Income (Expense) | Rail Infrastructure Operations and Assets [Member]
Supplementary Information [Line Items]
Gain (loss) on divestiture				$ 0	$ 233	$ 0