CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Apr. 01, 2018
Statement of Comprehensive Income [Abstract]
Net income before allocation to noncontrolling interests	[1],[2],[3],[4]	$ 3,889	$ 3,570
Foreign currency translation adjustments, net	[2]	324	758
Reclassification adjustments	[2]	2	15
Other comprehensive income (loss), foreign currency transaction and translation adjustment, before tax	[2]	326	773
Unrealized holding gains/(losses) on derivative financial instruments, net	[2]	267	(114)
Reclassification adjustments for (gains)/losses included in net income	[2],[5]	(263)	44
Other comprehensive income (loss), derivatives qualifying as hedges, before tax, total	[2]	4	(69)
Unrealized holding gains on available-for-sale securities, net	[2]	40	160
Reclassification adjustments for (gains)/losses included in net income	[2],[5]	11	(174)
Reclassification adjustments for unrealized gains included in Retained Earnings	[2],[6]	0	(462)
Other comprehensive income (loss), available-for-sale securities, before tax, total	[2]	51	(476)
Benefit plans: actuarial gains, net	[2]	0	163
Reclassification adjustments related to amortization	[2]	60	62
Reclassification adjustments related to settlements, net	[2]	0	37
Other	[2]	(23)	(86)
Defined benefit plan, amounts recognized in other comprehensive income (loss), net gain (loss), before tax, total	[2]	37	175
Reclassification adjustments related to amortization of prior service costs and other, net	[2]	(46)	(46)
Reclassification adjustments related to curtailments of prior service costs and other, net	[2]	0	(7)
Other	[2]	0	2
Defined benefit plan, amounts recognized in other comprehensive income (loss), net prior service cost, before tax	[2]	(46)	(51)
Other comprehensive income, before tax	[2]	372	352
Tax provision on other comprehensive income	[2]	25	432
Other comprehensive income/(loss) before allocation to noncontrolling interests	[2],[4]	348	(80)
Comprehensive income before allocation to noncontrolling interests	[2]	4,237	3,490
Less: Comprehensive income attributable to noncontrolling interests	[2]	1	10
Comprehensive income attributable to Pfizer Inc.	[2]	$ 4,236	$ 3,480

[1] Amounts may not add due to rounding.

[2] Amounts may not add due to rounding.

[3] Amounts may not add due to rounding.

[4] Amounts may not add due to rounding.

[5] Reclassified into Other (income)/deductions—net and Cost of sales in the condensed consolidated statements of income. For additional information on amounts reclassified into Cost of sales, see Note 7E. Financial Instruments: Derivative Financial Instruments and Hedging Activities.

[6] For additional information, see Note 1B. Basis of Presentation and Significant Accounting Policies: Adoption of New Accounting Standards in 2018 in our 2018 Financial Report.