Segment, Geographic and Other Revenue Information - Footnotes (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Segment Reporting Information [Line Items]
Income (charges) for certain legal matters	[1]	$ (15)	$ 88	$ (19)	$ 107
Business and legal entity alignment costs	[2]	137	1	256	4
Gains related to equity securities	[3],[4]	36	257	147	375
Loss on extinguishment of debt	[5]	0	0	138	3
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Cost reduction and productivity initiatives excluding acquisition related costs		113	42	170	93
Income (charges) for certain legal matters	[1]	(15)	88	(9)	107
Asset impairment charges		10	31	149	31
Business and legal entity alignment costs		141	1	264	4
Gains related to equity securities		25	257	136	375
Other charges		56	35	97	197
Special one-time bonus paid to all non-executive Pfizer colleagues					119
ViiV Healthcare Limited [Member]
Segment Reporting Information [Line Items]
Dividend income		$ 76	76	$ 140	135
Allogene [Member]
Segment Reporting Information [Line Items]
Non-cash pre-tax gain on contribution of assets			50		50
Allogene [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Non-cash pre-tax gain on contribution of assets					$ 50
Innovative Health Segment [Member] | ViiV Healthcare Limited [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Dividend income			$ 76

[1] In the second quarter and first six months of 2018, primarily represented the reversal of a legal accrual where a loss was no longer deemed probable.

[2] In the second quarter and first six months of 2019, represents incremental costs associated with the design, planning and implementation of our new organizational structure, effective in the beginning of 2019, and primarily includes consulting, legal, tax and advisory services. In the second quarter and first six months of 2018, represents expenses for changes to our infrastructure to align our commercial operations that existed through December 31, 2018, including costs to internally separate our businesses into distinct legal entities, as well as to streamline our intercompany supply operations to better support each business.

[3] 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.

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

[5] In the first six months of 2019, represents net losses due to the early retirement of debt in the first quarter of 2019, inclusive of the related termination of cross-currency swaps.