Restructuring Charges and Other Costs Associated with Acquisitions and Cost-Reduction/Productivity Initiatives - Footnotes (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019		Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charge (credit)	[1]	$ 83	$ 1	$ (50)	[2]	$ (32)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charge (credit)		79	7	15		(2)
Biopharma and Upjohn [Member] | Operating Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charge (credit)			$ (6)			$ (30)
Biopharma [Member] | Operating Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charge (credit)		10		(38)
Upjohn [Member] | Operating Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charge (credit)		(6)		(27)
Restructuring charges and acquisition-related costs [Member] | Array [Member]
Restructuring Cost and Reserve [Line Items]
Post-closing compensation expense for payments to Array employees for fair value of previously unvested stock options		$ 157		$ 157

[1] In the third quarter of 2019, restructuring charges mainly represent employee termination costs associated with cost-reduction and productivity initiatives as well as our acquisition of Array. In the first nine 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), partially offset by employee termination costs associated with cost-reduction and productivity initiatives, as well as our acquisition of Array. In the third quarter of 2018, restructuring charges were primarily due to accruals for exit costs and asset write downs related to our acquisition of Hospira, partially offset by the reversal of previously recorded accruals for employee termination costs. In the first nine months of 2018, restructuring credits were mostly related to the reversal of previously recorded accruals for employee termination costs. The restructuring activities for 2019 are associated with the following: • For the third quarter of 2019, Biopharma ($10 million charge); Upjohn ($6 million credit); and Other ($79 million charge). • For the first nine months of 2019, Biopharma ($38 million credit); Upjohn ($27 million credit); and Other ($15 million charge). The restructuring activities for 2018 are associated with the following: • For the third quarter of 2018, total reportable segments ($6 million credit); and Other ($7 million charge). • For the first nine months of 2018, total reportable segments ($30 million credit); and Other ($2 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.

[2] 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.