Planned Merger with DuPont (Details) - $ / shares	Dec. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 11, 2015
Planned Merger with DuPont [Line Items]
Common Stock, Par or Stated Value Per Share		$ 2.50	$ 2.50
Conversion of Stock, Shares Converted	4,000,000
Preferred stock, series A par value (in dollars per share)	$ 1.00	$ 1.00	$ 1.00
Stock Issued During Period, Shares, Conversion of Convertible Securities	96,800,000
Dow [Member]
Planned Merger with DuPont [Line Items]
Common Stock, Par or Stated Value Per Share				$ 2.50
Dow to DowDuPont Share Exchange Ratio for Common Shares				1
Dow and DuPont approximate Common Stock ownership				52.00%
DowDuPont [Member]
Planned Merger with DuPont [Line Items]
Proposed Merger, Common Stock, Par or Stated Value per Share				$ 0.01
DuPont [Member]
Planned Merger with DuPont [Line Items]
Common Stock, Par or Stated Value Per Share				$ 0.30
Dupont to DowDuPont share exchange ratio				1.2820
Dow and DuPont approximate Common Stock ownership				48.00%
$4.50 Series [Member] | DuPont [Member]
Planned Merger with DuPont [Line Items]
Preferred stock, series A par value (in dollars per share)				$ 4.50
$3.50 Series [Member] | DuPont [Member]
Planned Merger with DuPont [Line Items]
Preferred stock, series A par value (in dollars per share)				$ 3.50