Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income before allocation to noncontrolling interests		$ 9,652	$ 16,302	$ 11,188
Foreign currency translation adjustments, net		957	654	(799)
Reclassification adjustments		(17)	(288)	(22)
Other comprehensive income (loss), foreign currency transaction and translation adjustment, before tax, total		940	366	(821)
Unrealized holding gains/(losses) on derivative financial instruments, net		(582)	476	220
Reclassification adjustments for (gains)/losses included in net income	[1]	21	(664)	27
Other comprehensive income (loss), derivatives qualifying as hedges, before tax, total		(561)	(188)	247
Unrealized holding gains/(losses) on available-for-sale securities, net		361	(1)	(185)
Reclassification adjustments for (gains)/losses included in net income	[2]	(188)	39	124
Reclassification adjustments for unrealized gains included in Retained earnings	[3]	0	0	(462)
Other comprehensive income (loss), available-for-sale securities adjustment, before tax, total		173	38	(522)
Benefit plans: actuarial gains/(losses), net		(1,128)	(826)	(649)
Reclassification adjustments related to amortization		276	241	242
Reclassification adjustments related to settlements, net		278	274	142
Other		(189)	22	112
Defined benefit Plan, amounts recognized in other comprehensive income (loss), net gain (loss), before tax, total		(763)	(289)	(153)
Benefit plans: prior service (costs)/credits and other, net		52	(7)	(9)
Reclassification adjustments related to amortization of prior service costs and other, net		(176)	(181)	(181)
Reclassification adjustments related to curtailments of prior service costs and other, net		0	(2)	(19)
Other		0	1	2
Defined benefit plan, amounts recognized in other comprehensive income (loss), net prior service cost, before tax		(124)	(189)	(207)
Other comprehensive income/(loss), before tax		(335)	(262)	(1,457)
Tax provision/(benefit) on other comprehensive income/(loss)	[4]	(349)	115	518
Other comprehensive income/(loss) before allocation to noncontrolling interests		14	(376)	(1,975)
Comprehensive income before allocation to noncontrolling interests		9,666	15,926	9,214
Less: Comprehensive income/(loss) attributable to noncontrolling interests		27	18	16
Comprehensive income attributable to Pfizer Inc.		$ 9,639	$ 15,908	$ 9,198

[1] Reclassified into Other (income)/deductions—net and Cost of sales. See Note 7E.

[2] Reclassified into Other (income)/deductions—net.

[3] See Note 1B in our 2018 Financial Report.

[4] See Note 5E.