Segment, Geographic and Other Revenue Information - Footnotes (Detail) - USD ($) $ in Millions		1 Months Ended	3 Months Ended					9 Months Ended
		Sep. 30, 2018	Sep. 30, 2018		Jul. 01, 2018	Oct. 01, 2017		Sep. 30, 2018		Oct. 01, 2017
Segment Reporting Information [Line Items]
Income (charges) for certain legal matters	[1]		$ (37)			$ (183)		$ 70		$ (194)
Gain (loss) on sale of HIS net assets	[2]		2			12		1	[3]	(52)	[3]
Pre-tax gain associated with the formation of Cerevel	[5]		94	[4]		45		460	[4]	111
Business and legal entity alignment costs	[6]		0			16		4		54
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Cost reduction and productivity initiatives excluding acquisition related costs			35			55		127		133
Income (charges) for certain legal matters			(37)	[1]		(183)	[1]	70		(191)
Other income (charges)			282			(81)		84		(239)
Asset impairment charges						127		31		127
Business and legal entity alignment costs						16		4		54
Special one-time bonus paid to all non-executive Pfizer colleagues								119
HIS [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Gain (loss) on sale of HIS net assets			2			12		1		(52)
ViiV Healthcare Limited [Member] | IH [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Dividend income			91			$ 54		226		211
Allogene [Member]
Segment Reporting Information [Line Items]
Non-cash pre-tax gain from the difference between the fair value of equity investment received and book value of assets transferred					$ 50			$ 50
Laboratorio Teuto Brasilero [Member]
Segment Reporting Information [Line Items]
Loss on disposal of equity method investment										$ 30
Equity method investment, ownership percentage						40.00%				40.00%
Adjustment [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Costs and expenses						$ (19)				$ (40)
Adjustment [Member] | IH [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Costs and expenses						(125)				(344)
Adjustment [Member] | EH [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Costs and expenses						(36)				(114)
Bain Capital [Member] | Cerevel [Member]
Segment Reporting Information [Line Items]
Pre-tax gain associated with the formation of Cerevel		$ 343	$ 343
PUERTO RICO
Segment Reporting Information [Line Items]
Inventory losses, overhead costs related to when plants were not operation and incremental costs						$ 55				$ 55
Laboratorio Teuto Brasilero [Member]
Segment Reporting Information [Line Items]
Ownership percentage						60.00%				60.00%

[1] For the first nine months of 2018, the net credits primarily represent the reversal of a legal accrual where a loss was no longer deemed probable. In the third quarter and first nine months of 2017, primarily includes a $94 million charge to resolve a class action lawsuit filed by direct purchasers relating to Celebrex, which was approved by the court in April 2018, and a $79 million charge to reflect damages awarded by a jury in a patent matter.

[2] Represents adjustments to amounts previously recorded in 2016 to write down the HIS net assets to fair value less costs to sell related to the sale of HIS net assets to ICU Medical on February 3, 2017. For additional information, see Note 2B.

[3] Amounts may not add due to rounding.

[4] The net gains on investments in equity securities are reported in Other (income)/deductions––net and, for the third quarter and first nine months of 2018, include unrealized net gains on equity securities reflecting the adoption of a new accounting standard in the first quarter of 2018. For additional information, see Note 4.

[5] The net gains on investments in equity securities for the third quarter of 2018 include unrealized net gains on equity securities of $8 million and, for the first nine months of 2018, include unrealized net gains on equity securities of $344 million, reflecting the adoption of a new accounting standard in the first quarter of 2018. We continue to hold 2.5 million shares of ICU Medical common stock and we recognized unrealized gains of $24 million in the third quarter of 2018 and unrealized gains of $229 million in the first nine months of 2018 related to these remaining shares. Prior to the adoption of a new accounting standard in the first quarter of 2018, net unrealized gains and losses on virtually all equity securities with readily determinable fair values were reported in Accumulated other comprehensive income. For additional information, see Note 1B, Note 2B and Note 7B.

[6] Represents expenses for changes to our infrastructure to align our commercial operations of our current segments, 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.