Summary of Sundry Income (Expense) - Net (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Sundry income (expense) - net	$ (81)	$ 69
Gain (Loss) on Extinguishment of Debt	(86)
Corporate Segment [Member]
Gain (Loss) on Extinguishment of Debt	(86)
The Dow Chemical Company [Domain]
Sundry income (expense) - net	$ (82)	$ 69

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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