Business Combinations Fair Value of Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Aug. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	$ 46,446	$ 45,589
Merger with Dow [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Cash and cash equivalents			$ 4,005
Marketable securities			2,849
Accounts and notes receivable			7,847
Inventories			8,807
Other current assets			360
Investment in nonconsolidated affiliates			1,626
Assets held for sale - current			3,732
Property, plant and equipment			11,843
Goodwill			45,387
Other intangible assets			27,141
Deferred income tax assets			284
Other assets			2,076
Total assets			115,957
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Short term borrowings and capital lease obligations			5,319
Accounts payable			3,285
Income taxes payable			261
Accrued and other current liabilities			3,517
Liabilities held for sale - current			125
Long-term Debt			9,878
Deferred income tax liabilities			8,419
Pension and other post employment benefits Noncurrent			8,056
Other noncurrent obligations			1,944
Total liabilities			40,804
Noncontrolling interest			234
Preferred stock			239
Fair value of net assets			$ 74,680