Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassifications
Cash Segregated under Commodity Exchange Act Regulation	$ 1,000
Net Cash Provided by (Used in) Operating Activities	2,211	$ 1,555	$ 1,705
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, at Carrying Value	1,858	1,561	1,796	$ 2,761
Receivables
Allowance for Doubtful Accounts Receivable	73	72
Trade accounts receivable due from unconsolidated affiliates	343	232
Property, Plant, and Equipment
Capitalized interest on major construction projects	17	20	11
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Asset Impairment	0	11	21
Asset Abandonments and Write-Downs
Other Asset Impairment Charges	101	17	108
Revenues
Revenues from unconsolidated affiliates	6,000	4,200	5,000
Research and Development
Research and development expenses, net of expenditures subsequently reimbursed by government grants	$ 129	123	122
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Cumulative Effect of New Accounting Principle in Period of Adoption		(7)
Minimum [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Asset, Useful Life	2 years
Minimum [Member] | Building [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	15 years
Minimum [Member] | Machinery And Equipment [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Asset, Useful Life	50 years
Maximum [Member] | Building [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	40 years
Maximum [Member] | Machinery And Equipment [Member]
Property, Plant, and Equipment
Property, Plant and Equipment, Useful Life	40 years
Cost Of Products Sold [Member]
Reclassifications
Floor Brokerage, Exchange and Clearance Fees	$ 64	65	54
Selling, General and Administrative Expenses [Member]
Reclassifications
Floor Brokerage, Exchange and Clearance Fees		(65)	(54)
ASU 2016-16 Income Taxes [Member]
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Cumulative Effect of New Accounting Principle in Period of Adoption		(7)
Restatement Adjustment [Member]
Reclassifications
Net Cash Provided by (Used in) Operating Activities		80	765
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, at Carrying Value		$ 873	$ 793