Dow Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,932	$ (217)	$ 2,938	$ 41
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on investments	17	76	(32)	(24)
Cumulative translation adjustments	65	63	(188)	(100)
Pension and other postretirement benefit plans	149	141	1,283	283
Derivative instruments	6	24	116	(138)
Other Comprehensive Income (Loss), Net of Tax	237	304	1,179	21
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	2,169	87	4,117	62
Comprehensive income attributable to noncontrolling interests, net of tax	31	8	46	27
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 2,138	$ 79	$ 4,071	$ 35