Restructuring Charges and Other Costs Associated with Acquisitions and Cost-Reduction/Productivity Initiatives - Restructuring Accruals (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019		Jul. 01, 2018
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	[1]			$ 1,252
Provision/(credit)(b)	[2]	$ (144)	$ (24)	(134)	[3]	$ (33)
Utilization and other	[4]			(321)
Balance, June 30, 2019	[5]	797		797
Employee Termination Costs [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	[1]			1,203
Provision/(credit)(b)	[3]			(167)
Utilization and other	[4]			(303)
Balance, June 30, 2019	[5]	733		733
Asset Impairment Charges [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	[1]			0
Provision/(credit)(b)	[3]			0
Utilization and other	[4]			0
Balance, June 30, 2019	[5]	0		0
Exit Costs [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	[1]			49
Provision/(credit)(b)	[3]			34
Utilization and other	[4]			(18)
Balance, June 30, 2019	[5]	$ 64		$ 64

[1] Included in Other current liabilities ($823 million) and Other noncurrent liabilities ($428 million).

[2] In the second quarter and first six months of 2019, restructuring credits mostly represent the reversal of certain accruals related to our acquisition of Wyeth upon the effective favorable settlement of a U.S. IRS audit for multiple tax years (see Note 5B). In the three and six months ended July 1, 2018, restructuring credits were associated with cost-reduction and productivity initiatives not associated with acquisitions, as well as acquisition-related costs, primarily associated with Hospira. The restructuring activities for 2019 are associated with the following: • For the second quarter of 2019, Biopharma ($62 million credit); Upjohn ($9 million credit); and Other ($74 million credit). • For the first six months of 2019, Biopharma ($48 million credit); Upjohn ($22 million credit); and Other ($63 million credit). The restructuring activities for 2018 are associated with the following: • For the second quarter of 2018, total reportable segments ($10 million credit); and Other ($13 million credit). • For the first six months of 2018, total reportable segments ($24 million credit); and Other ($9 million credit). At the beginning of fiscal 2019, we revised our operating segments and are unable to directly associate these prior-period restructuring charges with the new individual segments.

[3] Includes the reversal of certain accruals related to our acquisition of Wyeth upon the effective favorable settlement of a U.S. IRS audit for multiple tax years. See Note 5B for additional information.

[4] Includes adjustments for foreign currency translation.

[5] Included in Other current liabilities ($593 million) and Other noncurrent liabilities ($204 million).