Other (Income)/Deductions - Net - Footnotes (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Loss Contingencies [Line Items]
Proceeds from favorable resolution of legal dispute		$ 82
Gains related to equity securities	[1],[2]	36	$ 257	$ 147	$ 375
Intangible asset impairment charge		10	31	10	31
Other asset impairments				20
Change in fair value of contingent consideration		81	23		135
Income from insurance recoveries		25		50
Allogene [Member]
Loss Contingencies [Line Items]
Non-cash pre-tax gain on contribution of assets			50		50
ViiV Healthcare Limited [Member]
Loss Contingencies [Line Items]
Dividend income		$ 76	76	140	135
Mylan [Member] | Collaborative Arrangement [Member]
Loss Contingencies [Line Items]
Milestone payment received				68
Shire [Member] | Licensing Arrangement [Member]
Loss Contingencies [Line Items]
Proceeds from licensing arrangement					75
Merck [Member] | Collaborative Arrangement [Member]
Loss Contingencies [Line Items]
Milestone payment received					40
Disposed of by Sale [Member] | HIS [Member]
Loss Contingencies [Line Items]
Gains related to equity securities			142		203
Disposed of by Sale [Member] | Phase 2b Ready AMPA Receptor Potentiator For CIAS [Member]
Loss Contingencies [Line Items]
Consideration transferred			75		75
Developed Technology Rights [Member]
Loss Contingencies [Line Items]
Intangible asset impairment charge	[3]			50
In Process Research and Development [Member]
Loss Contingencies [Line Items]
Intangible asset impairment charge	[3]			90
Pfizer's Worldwide Research, Development And Medical [Member] | In Process Research and Development [Member]
Loss Contingencies [Line Items]
Intangible asset impairment charge				90
Biopharma [Member] | Operating Segments [Member] | Developed Technology Rights [Member]
Loss Contingencies [Line Items]
Intangible asset impairment charge				$ 40
Other Nonoperating Income (Expense) [Member] | Licensing Arrangement [Member]
Loss Contingencies [Line Items]
Milestone payment received			88
Mylotarg [Member] | EU [Member] | Developed Technology Rights [Member]
Loss Contingencies [Line Items]
Non-cash gain on cash settlement of liability			$ 17		$ 17

[1] The second quarter of 2018 included gains of $142 million and the first six months of 2018 included gains of $203 million related to our investment in ICU Medical stock. For additional information, see Note 7B.

[2] The net gains on investments in equity securities are reported in Other (income)/deductions––net. For additional information, see Note 4.

[3] Reflects intangible assets written down to fair value in the first six months of 2019. Fair value was determined using the income approach, specifically the multi-period excess earnings method, also known as the discounted cash flow method. We started with a forecast of all the expected net cash flows associated with the asset and then applied an asset-specific discount rate to arrive at a net present value amount. Some of the more significant estimates and assumptions inherent in this approach include: the amount and timing of the projected net cash flows, which includes the expected impact of competitive, legal and/or regulatory forces on the product; the discount rate, which seeks to reflect the various risks inherent in the projected cash flows; and the tax rate, which seeks to incorporate the geographic diversity of the projected cash flows.