Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2024	Jul. 01, 2023	Jun. 29, 2024	Jul. 01, 2023
Comprehensive income
Net income	$ 1,553	$ 1,362	$ 2,885	$ 2,654
Currency translation adjustment:
Currency translation adjustment (net of tax provision (benefit) of $88, $0, $255 and $(36))	346	125	802	169
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, $0 and $1)	1	1	1	4
Pension and other postretirement benefit liability adjustments:
Pension and other postretirement benefit liability adjustments arising during the period (net of tax (provision) benefit of $0, $1, $0 and $0)	0	(1)	1	0
Amortization of net loss included in net periodic pension cost (net of tax (provision) benefit of $0, $0, $0 and $0)	1	(2)	1	(2)
Total other comprehensive income/(loss)	348	123	805	171
Comprehensive income	1,901	1,485	3,689	2,825
Less: comprehensive income/(loss) attributable to noncontrolling interests and redeemable noncontrolling interest	3	(6)	3	0
Comprehensive income attributable to Thermo Fisher Scientific Inc.	$ 1,899	$ 1,491	$ 3,686	$ 2,825