CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2024	Sep. 30, 2023	Sep. 28, 2024	Sep. 30, 2023
Comprehensive income
Net income	$ 1,629	$ 1,695	$ 4,514	$ 4,349
Currency translation adjustment:
Currency translation adjustment (net of tax provision (benefit) of $(244), $71, $10 and $35)	(54)	(112)	748	57
Unrealized gains/(losses) on available-for-sale debt securities
Unrealized holding losses arising during the period (net of tax (provision) benefit of $0, $0, $0 and $0)	0	0	(1)	0
Unrealized gains/(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	2	5
Pension and other postretirement benefit liability adjustments:
Pension and other postretirement benefit liability adjustments arising during the period (net of tax (provision) benefit of $2, $(1), $2 and $(1))	(5)	2	(4)	2
Amortization of net loss included in net periodic pension cost (net of tax (provision) benefit of $0, $(1), $1 and $(1))	0	0	2	(2)
Total other comprehensive income/(loss)	(58)	(109)	747	62
Comprehensive income	1,572	1,586	5,261	4,411
Less: comprehensive income/(loss) attributable to noncontrolling interests and redeemable noncontrolling interest	6	(26)	9	(26)
Comprehensive income attributable to Thermo Fisher Scientific Inc.	$ 1,566	$ 1,612	$ 5,252	$ 4,437