CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Statement of Comprehensive Income [Abstract]
Net income before allocation to noncontrolling interests		$ 2,202	$ 7,684	$ 9,046	$ 16,628
Foreign currency translation adjustments, net	[1]	1,609	(468)	96	(628)
Reclassification adjustments		0	268	0	270
Other comprehensive income (loss), foreign currency transaction and translation adjustment, before tax		1,609	(200)	96	(358)
Unrealized holding gains/(losses) on derivative financial instruments, net		(372)	150	(661)	241
Reclassification adjustments for (gains)/losses included in net income	[2]	143	(29)	(25)	(372)
Other comprehensive income (loss), derivatives qualifying as hedges, before tax, total		(230)	122	(685)	(131)
Unrealized holding gains/(losses) on available-for-sale securities, net		239	15	231	48
Reclassification adjustments for (gains)/losses included in net income	[3]	(85)	(7)	(25)	30
Other comprehensive income (loss), available-for-sale securities, before tax, total		155	8	205	77
Benefit plans: actuarial gains/(losses), net		(1,211)	(171)	(1,372)	(175)
Reclassification adjustments related to amortization		67	60	200	180
Reclassification adjustments related to settlements, net		174	38	240	40
Other		(206)	42	(123)	60
Benefit plans: amounts recognized in other comprehensive income (loss), net gain (loss), before tax, total		(1,177)	(31)	(1,055)	105
Benefit plans: prior service (costs)/credits and other, net		0	0	0	(1)
Reclassification adjustments related to amortization of prior service costs and other, net		(45)	(44)	(134)	(137)
Reclassification adjustments related to curtailments of prior service costs and other, net		0	(46)	0	(46)
Other		(3)	3	1	4
Defined benefit plan, amounts recognized in other comprehensive income (loss), net prior service cost, before tax		(47)	(88)	(133)	(180)
Other comprehensive income/(loss), before tax		310	(190)	(1,572)	(486)
Tax provision/(benefit) on other comprehensive income/(loss)		(262)	84	(527)	50
Other comprehensive income/(loss) before allocation to noncontrolling interests		572	(275)	(1,045)	(536)
Comprehensive income before allocation to noncontrolling interests		2,774	7,409	8,001	16,092
Less: Comprehensive income/(loss) attributable to noncontrolling interests		11	(6)	16	8
Comprehensive income attributable to Pfizer Inc.		$ 2,763	$ 7,415	$ 7,986	$ 16,084

[1] Amounts in the third quarter of 2020 primarily include gains from the strengthening of certain major currencies against the U.S. dollar and a net gain related to foreign currency translation adjustments and the impact of our net investment hedging program, both attributable to our equity method investment in the GSK Consumer Healthcare joint venture. Amounts in the first nine months of 2020 primarily include gains from the strengthening of certain major currencies against the U.S. dollar, partially offset by a net loss related to foreign currency translation adjustments and the impact of our net investment hedging program, both attributable to our equity method investment in the GSK Consumer Healthcare joint venture. See Note 2B.

[2] Reclassified into Other (income)/deductions—net and Cost of sales in the condensed consolidated statements of income. See Note 7E.

[3] Reclassified into Other (income)/deductions—net in the condensed consolidated statements of income.