Nature of Operations, Basis of Presentation and Change in Accounting Principle (Details 2) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2014	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Jan. 01, 2015
Statement of Results of Operations
Cost of goods sold		$ 6,527	$ 7,872	$ 20,768	$ 25,306
Selling, general and administrative expenses		992	1,129	3,203	3,696
Research and development expenses		453	513	1,429	1,547
Other operating (income) expenses		560	381	1,356	1,032
Total operating costs		8,679	10,037	27,203	32,021
Operating profit		481	925	1,760	3,960
Other income (expense)		28	(15)	112	107
Consolidated profit before taxes		383	783	1,487	3,686
Provision (benefit) for income taxes		96	218	372	1,074
Profit of consolidated companies		287	565	1,115	2,612
Profit of consolidated and affiliated companies		283	562	1,108	2,613
Profit	[1]	$ 283	$ 559	$ 1,104	$ 2,606
Profit per common share (in dollars per share)		$ 0.48	$ 0.95	$ 1.89	$ 4.36
Profit per common share - diluted (in dollars per share)	[2]	$ 0.48	$ 0.94	$ 1.88	$ 4.30
Statement of Comprehensive Income
Profit of consolidated and affiliated companies		$ 283	$ 562	$ 1,108	$ 2,613
Foreign currency translation, net of tax		137	(236)	442	(806)
Pension and other postretirement benefits: Current year actuarial gain (loss), net of tax		0	0	0	0
Pension and other postretirement benefits: Amortization of actuarial (gain) loss, net of tax		0	0	0	0
Total other comprehensive income (loss), net of tax		106	(268)	508	(811)
Comprehensive income		389	294	1,616	1,802
Comprehensive income attributable to stockholders		389	292	1,612	1,804
Statement of Financial Position
Noncurrent deferred and refundable income taxes		2,579		2,579				$ 2,489
Liability for postemployment benefits		8,499		8,499				8,843
Profit employed in the business		29,450		29,450				29,246
Accumulated other comprehensive income (loss)		(1,527)	(1,861)	(1,527)	(1,861)	$ (1,059)	$ (1,633)	(2,035)	$ (1,594)
Statement of Stockholders' Equity
Profit of consolidated and affiliated companies		283	562	1,108	2,613
Foreign currency translation, net of tax		137	(236)	442	(806)
Pension and other postretirement benefits, net of tax				90	(25)
Total stockholders' equity		15,715	15,995	15,715	15,995	16,826		14,885
Statement of Cash Flow
Profit of consolidated and affiliated companies		283	562	1,108	2,613
Adjustments for non-cash items: Other				640	323
Other assets - net				(141)	96
Other liabilities - net				(291)	(236)
Effect of Accounting Change
Change in Accounting Principle
Cumulative effect of change on equity										$ 5,400
Cumulative effect of change on equity, net of tax						$ 2,900
Statement of Results of Operations
Cost of goods sold		(61)	(82)	(181)	(253)
Selling, general and administrative expenses		(33)	(96)	(102)	(236)
Research and development expenses		(11)	(21)	(32)	(65)
Other operating (income) expenses		0	(13)	0	(36)
Total operating costs		(105)	(212)	(315)	(590)
Operating profit		105	212	315	590
Other income (expense)		15	53	52	31
Consolidated profit before taxes		120	265	367	621
Provision (benefit) for income taxes		41	74	120	204
Profit of consolidated companies		79	191	247	417
Profit of consolidated and affiliated companies		79	191	247	417
Profit		$ 79	$ 191	$ 247	$ 417
Profit per common share (in dollars per share)		$ 0.13	$ 0.32	$ 0.42	$ 0.70
Profit per common share - diluted (in dollars per share)		$ 0.13	$ 0.32	$ 0.42	$ 0.68
Statement of Comprehensive Income
Profit of consolidated and affiliated companies		$ 79	$ 191	$ 247	$ 417
Foreign currency translation, net of tax		(2)	(1)	(5)	4
Pension and other postretirement benefits: Current year actuarial gain (loss), net of tax		2	(44)	5	(68)
Pension and other postretirement benefits: Amortization of actuarial (gain) loss, net of tax		(79)	(108)	(237)	(326)
Total other comprehensive income (loss), net of tax		(79)	(153)	(237)	(390)
Comprehensive income		0	38	10	27
Comprehensive income attributable to stockholders		0	38	10	27
Statement of Financial Position
Noncurrent deferred and refundable income taxes		(11)		(11)
Liability for postemployment benefits		(21)		(21)
Profit employed in the business		(4,715)		(4,715)				(4,962)
Accumulated other comprehensive income (loss)		4,725		4,725				4,962
Statement of Stockholders' Equity
Profit of consolidated and affiliated companies		79	191	247	417
Foreign currency translation, net of tax		(2)	(1)	(5)	4
Pension and other postretirement benefits, net of tax				(232)	(394)
Total stockholders' equity		10	27	10	27
Statement of Cash Flow
Profit of consolidated and affiliated companies		79	191	247	417
Adjustments for non-cash items: Other				(52)	(31)
Other assets - net				120	204
Other liabilities - net				(315)	(590)
Previous Accounting Method
Statement of Results of Operations
Cost of goods sold		6,588		20,949
Selling, general and administrative expenses		1,025		3,305
Research and development expenses		464		1,461
Other operating (income) expenses		560		1,356
Total operating costs		8,784		27,518
Operating profit		376		1,445
Other income (expense)		13		60
Consolidated profit before taxes		263		1,120
Provision (benefit) for income taxes		55		252
Profit of consolidated companies		208		868
Profit of consolidated and affiliated companies		204		861
Profit		$ 204		$ 857
Profit per common share (in dollars per share)		$ 0.35		$ 1.47
Profit per common share - diluted (in dollars per share)		$ 0.35		$ 1.46
Statement of Comprehensive Income
Profit of consolidated and affiliated companies		$ 204		$ 861
Foreign currency translation, net of tax		139		447
Pension and other postretirement benefits: Current year actuarial gain (loss), net of tax		(2)		(5)
Pension and other postretirement benefits: Amortization of actuarial (gain) loss, net of tax		79		237
Total other comprehensive income (loss), net of tax		185		745
Comprehensive income		389		1,606
Comprehensive income attributable to stockholders		389		1,602
Statement of Financial Position
Noncurrent deferred and refundable income taxes		2,590		2,590
Liability for postemployment benefits		8,520		8,520
Profit employed in the business		34,165		34,165
Accumulated other comprehensive income (loss)		(6,252)		(6,252)
Statement of Stockholders' Equity
Profit of consolidated and affiliated companies		204		861
Foreign currency translation, net of tax		139		447
Pension and other postretirement benefits, net of tax				322
Total stockholders' equity		15,705		15,705
Statement of Cash Flow
Profit of consolidated and affiliated companies		$ 204		861
Adjustments for non-cash items: Other				692
Other assets - net				(261)
Other liabilities - net				$ 24
Previously Reported
Statement of Results of Operations
Cost of goods sold			7,954		25,559
Selling, general and administrative expenses			1,225		3,932
Research and development expenses			534		1,612
Other operating (income) expenses			394		1,068
Total operating costs			10,249		32,611
Operating profit			713		3,370
Other income (expense)			(68)		76
Consolidated profit before taxes			518		3,065
Provision (benefit) for income taxes			144		870
Profit of consolidated companies			374		2,195
Profit of consolidated and affiliated companies			371		2,196
Profit			$ 368		$ 2,189
Profit per common share (in dollars per share)			$ 0.63		$ 3.66
Profit per common share - diluted (in dollars per share)			$ 0.62		$ 3.62
Statement of Comprehensive Income
Profit of consolidated and affiliated companies			$ 371		$ 2,196
Foreign currency translation, net of tax			(235)		(810)
Pension and other postretirement benefits: Current year actuarial gain (loss), net of tax			44		68
Pension and other postretirement benefits: Amortization of actuarial (gain) loss, net of tax			108		326
Total other comprehensive income (loss), net of tax			(115)		(421)
Comprehensive income			256		1,775
Comprehensive income attributable to stockholders			254		1,777
Statement of Financial Position
Profit employed in the business								34,208
Accumulated other comprehensive income (loss)								$ (6,997)
Statement of Stockholders' Equity
Profit of consolidated and affiliated companies			371		2,196
Foreign currency translation, net of tax			(235)		(810)
Pension and other postretirement benefits, net of tax					369
Total stockholders' equity			15,968		15,968
Statement of Cash Flow
Profit of consolidated and affiliated companies			$ 371		2,196
Adjustments for non-cash items: Other					354
Other assets - net					(108)
Other liabilities - net					$ 354

[1] 1 Profit attributable to common stockholders.

[2] 2 Diluted by assumed exercise of stock-based compensation awards using the treasury stock method.