Accounting and Reporting Developments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used by operating activities			$ (492)	$ (475)
Net cash provided by investing activities			(3,792)	312
Beneficial interests obtained in securitized receivables	$ 407	$ 538
Cost of products sold	2,466	1,732	4,274	3,263
Reclassification of net benefit to pension and other postretirement	$ 17	12	$ 34	24
Cumulative effect of change in accounting principle						$ 3
Accounting Standards Update 2016-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used by operating activities		507
Net cash provided by investing activities		257
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products sold		(12)
Retained Earnings | Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle					$ (3)
Accumulated Other Comprehensive Income | Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle					$ 3
Cost of Goods, Total [Member] | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of net benefit to pension and other postretirement		13		25
Selling, General and Administrative Expenses [Member] | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of net benefit to pension and other postretirement		$ 1		$ 1