Acquisitions and Dispositions Discontinued Operations (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 28, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Separation And Merger Transaction [Line Items]
Common stock available for distribution in exchange	35,200,000.0
Final exchange ratio	3.2562
Treasury Stock, Shares, Acquired	21,650,454
Increase in treasury stock as a result of tender offer, noncash financing activity	$ 1,561
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax		$ 1,468
Income from discontinued operations, net of tax				$ 1	$ 1,002	$ 2,380
Less: net income attributable to noncontrolling interests				$ 21	$ 57	122
Proceeds from separation of business	900	1,735
Cash Divested from Deconsolidation	27
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		$ 946	$ 2,200
Value of shares to be received in new company after separation of business	1,800
Commodity Chemicals Segment
Separation And Merger Transaction [Line Items]
Disposal Group, Including Discontinued Operation, Revenue						108
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax						2,192
Discontinued Operation, Tax Effect of Discontinued Operation						$ (5)
Proceeds from separation of business	67
Pensions | Commodity Chemicals Segment
Separation And Merger Transaction [Line Items]
Net partial settlement loss	$ 33