Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022
Comprehensive income
Net income	$ 1,695	$ 1,498	$ 4,349	$ 5,386
Currency translation adjustment:
Currency translation adjustment (net of tax provision (benefit) of $71, $157, $35 and $419)	(112)	(216)	57	(632)
Unrealized gains and losses on hedging instruments:
Reclassification adjustment for losses included in net income (net of tax (provision) benefit of $0, $0, $1 and $1)	1	1	5	2
Pension and other postretirement benefit liability adjustments:
Pension and other postretirement benefit liability adjustments arising during the period (net of tax (provision) benefit of $(1), $(3), $(1) and $(6))	2	4	2	13
Amortization of net loss included in net periodic pension cost (net of tax (provision) benefit of $(1), $0, $(1) and $2)	0	4	(2)	8
Total other comprehensive income/(loss)	(109)	(207)	62	(609)
Comprehensive income	1,586	1,291	4,411	4,777
Less: comprehensive income/(loss) attributable to noncontrolling interests and redeemable noncontrolling interest	(26)	0	(26)	2
Comprehensive income attributable to Thermo Fisher Scientific Inc.	$ 1,612	$ 1,291	$ 4,437	$ 4,775