Restructuring Charges and Other Costs Associated with Acquisitions and Cost-Reduction/Productivity Initiatives - Restructuring Accruals - Footnotes (Detail) - USD ($) $ in Millions	Sep. 30, 2018		Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 796	[1]	$ 1,105	[2]
Other Current Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	397		643
Other Noncurrent Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 399		$ 462

[1] Included in Other current liabilities ($397 million) and Other noncurrent liabilities ($399 million).

[2] Included in Other current liabilities ($643 million) and Other noncurrent liabilities ($462 million).