Debt and Other Financing Arrangements - Schedule of Outstanding Debt (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 28, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Total borrowings at par value	$ 35,303	$ 31,332
Unamortized discount	(98)	(95)
Unamortized debt issuance costs	(172)	(164)
Total borrowings at carrying value	35,033	31,072
Finance lease liabilities	196	202
Less: Short-term obligations and current maturities	2,214	2,214
Long-term obligations	33,015	29,061
Senior Notes
Debt Instrument [Line Items]
Total borrowings at carrying value	$ 35,031	30,999
Senior Notes \| 0.125% 5.5-Year Senior Notes, Due 3/1/2025 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	0.125%
Term	5 years 6 months
Total borrowings at par value		828
Senior Notes \| 2.00% 10-Year Senior Notes, Due 4/15/2025 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	2.00%
Term	10 years
Total borrowings at par value		663
Senior Notes \| 0.853% 3-Year Senior Notes, Due 10/20/2025 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	0.853%
Term	3 years
Effective interest rate	1.05%
Total borrowings at par value	$ 154	142
Senior Notes \| 0.00% 4-Year Senior Notes, Due 11/18/2025 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	0.00%
Term	4 years
Effective interest rate	0.16%
Total borrowings at par value	$ 644	569
Senior Notes \| 3.20% 3-Year Senior Notes, Due 1/21/2026 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	3.20%
Term	3 years
Effective interest rate	3.38%
Total borrowings at par value	$ 586	518
Senior Notes \| 1.40% 8.5-Year Senior Notes, Due 1/23/2026 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.40%
Term	8 years 6 months
Effective interest rate	1.53%
Total borrowings at par value	$ 820	725
Senior Notes \| 4.953% 3-Year Senior Notes, Due 8/10/2026
Debt Instrument [Line Items]
Interest rate	4.953%
Term	3 years
Effective interest rate	5.18%
Total borrowings at par value	$ 600	600
Senior Notes \| 0.832% 1.5-Year Senior Notes, Due 9/7/2026 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	0.832%
Term	1 year 6 months
Effective interest rate	1.14%
Total borrowings at par value	$ 513	0
Senior Notes \| 5.00% 3-Year Senior Notes, Due 12/5/2026
Debt Instrument [Line Items]
Interest rate	5.00%
Term	3 years
Effective interest rate	5.26%
Total borrowings at par value	$ 1,000	1,000
Senior Notes \| 1.45% 10-Year Senior Notes, Due 3/16/2027 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.45%
Term	10 years
Effective interest rate	1.66%
Total borrowings at par value	$ 586	518
Senior Notes \| 1.75% 7-Year Senior Notes, Due 4/15/2027 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.75%
Term	7 years
Effective interest rate	1.97%
Total borrowings at par value	$ 703	621
Senior Notes \| 1.054% 5-Year Senior Notes, Due 10/20/2027 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	1.054%
Term	5 years
Effective interest rate	1.18%
Total borrowings at par value	$ 200	184
Senior Notes \| 4.80% 5-Year Senior Notes, Due 11/21/2027
Debt Instrument [Line Items]
Interest rate	4.80%
Term	5 years
Effective interest rate	5.00%
Total borrowings at par value	$ 600	600
Senior Notes \| 0.790% 3-Year Senior Notes, Due 1/6/2028 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	0.79%
Term	3 years
Effective interest rate	1.35%
Total borrowings at par value	$ 110	0
Senior Notes \| 0.50% 8.5-Year Senior Notes, Due 3/1/2028 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	0.50%
Term	8 years 6 months
Effective interest rate	0.78%
Total borrowings at par value	$ 937	828
Senior Notes \| 1.6525% 4-Year Senior Notes, Due 3/7/2028 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.6525%
Term	4 years
Effective interest rate	1.79%
Total borrowings at par value	$ 413	364
Senior Notes \| 0.77% 5-Year Senior Notes, Due 9/6/2028 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	0.77%
Term	5 years
Effective interest rate	0.90%
Total borrowings at par value	$ 200	184
Senior Notes \| 1.375% 12-Year Senior Notes, Due 9/12/2028 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.375%
Term	12 years
Effective interest rate	1.46%
Total borrowings at par value	$ 703	621
Senior Notes \| 1.75% 7-Year Senior Notes, Due 10/15/2028
Debt Instrument [Line Items]
Interest rate	1.75%
Term	7 years
Effective interest rate	1.89%
Total borrowings at par value	$ 700	700
Senior Notes \| 5.00% 5-Year Senior Notes, Due 1/31/2029
Debt Instrument [Line Items]
Interest rate	5.00%
Term	5 years
Effective interest rate	5.24%
Total borrowings at par value	$ 1,000	1,000
Senior Notes \| 1.125% 4-Year Senior Notes, Due 3/7/2029 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.125%
Term	4 years
Effective interest rate	1.26%
Total borrowings at par value	$ 394	0
Senior Notes \| 1.95% 12-Year Senior Notes, Due 7/24/2029 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.95%
Term	12 years
Effective interest rate	2.08%
Total borrowings at par value	$ 820	725
Senior Notes \| 2.60% 10-Year Senior Notes, Due 10/1/2029
Debt Instrument [Line Items]
Interest rate	2.60%
Term	10 years
Effective interest rate	2.74%
Total borrowings at par value	$ 900	900
Senior Notes \| 1.279% 7-Year Senior Notes, Due 10/19/2029 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	1.279%
Term	7 years
Effective interest rate	1.44%
Total borrowings at par value	$ 32	30
Senior Notes \| 1.120% 5-Year Senior Notes, Due 1/6/2030 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.12%
Term	5 years
Effective interest rate	1.25%
Total borrowings at par value	$ 293	0
Senior Notes \| 4.977% 7-Year Senior Notes, Due 8/10/2030
Debt Instrument [Line Items]
Interest rate	4.977%
Term	7 years
Effective interest rate	5.12%
Total borrowings at par value	$ 750	750
Senior Notes \| 0.80% 9-Year Senior Notes, Due 10/18/2030 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	0.80%
Term	9 years
Effective interest rate	0.89%
Total borrowings at par value	$ 2,051	1,812
Senior Notes \| 0.875% 12-Year Senior Notes, Due 10/1/2031 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	0.875%
Term	12 years
Effective interest rate	1.14%
Total borrowings at par value	$ 1,055	932
Senior Notes \| 2.00% 10-Year Senior Notes, Due 10/15/2031
Debt Instrument [Line Items]
Interest rate	2.00%
Term	10 years
Effective interest rate	2.23%
Total borrowings at par value	$ 1,200	1,200
Senior Notes \| 1.8401% 8-Year Senior Notes, Due 3/8/2032 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.8401%
Term	8 years
Effective interest rate	1.92%
Total borrowings at par value	$ 519	457
Senior Notes \| 2.375% 12-Year Senior Notes, Due 4/15/2032 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	2.375%
Term	12 years
Effective interest rate	2.55%
Total borrowings at par value	$ 703	621
Senior Notes \| 1.49% 10-Year Senior Notes, Due 10/20/2032 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	1.49%
Term	10 years
Effective interest rate	1.60%
Total borrowings at par value	$ 44	40
Senior Notes \| 4.95% 10-Year Senior Notes, Due 11/21/2032
Debt Instrument [Line Items]
Interest rate	4.95%
Term	10 years
Effective interest rate	5.09%
Total borrowings at par value	$ 600	600
Senior Notes \| 1.4175% 8-Year Senior Notes, Due 3/7/2033 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.4175%
Term	8 years
Effective interest rate	1.49%
Total borrowings at par value	$ 438	0
Senior Notes \| 5.086% 10-Year Senior Notes, Due 8/10/2033
Debt Instrument [Line Items]
Interest rate	5.086%
Term	10 years
Effective interest rate	5.20%
Total borrowings at par value	$ 1,000	1,000
Senior Notes \| 1.125% 12-Year Senior Notes, Due 10/18/2033 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.125%
Term	12 years
Effective interest rate	1.21%
Total borrowings at par value	$ 1,758	1,553
Senior Notes \| 5.20% 10-Year Senior Notes, Due 1/31/2034
Debt Instrument [Line Items]
Interest rate	5.20%
Term	10 years
Effective interest rate	5.34%
Total borrowings at par value	$ 500	500
Senior Notes \| 3.65% 12-Year Senior Notes, Due 11/21/2034 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	3.65%
Term	12 years
Effective interest rate	3.76%
Total borrowings at par value	$ 879	777
Senior Notes \| 1.50% 12-Year Senior Notes, Due 9/6/2035 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	1.50%
Term	12 years
Effective interest rate	1.58%
Total borrowings at par value	$ 149	137
Senior Notes \| 2.0375% 12-Year Senior Notes, Due 3/7/2036 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	2.0375%
Term	12 years
Effective interest rate	2.10%
Total borrowings at par value	$ 407	358
Senior Notes \| 1.520% 12-Year Senior Notes, Due 1/6/2037 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.52%
Term	12 years
Effective interest rate	1.56%
Total borrowings at par value	$ 389	0
Senior Notes \| 1.6524% 12-Year Senior Notes, Due 3/6/2037 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.6524%
Term	12 years
Effective interest rate	1.71%
Total borrowings at par value	$ 269	0
Senior Notes \| 2.875% 20-Year Senior Notes, Due 7/24/2037 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	2.875%
Term	20 years
Effective interest rate	2.94%
Total borrowings at par value	$ 820	725
Senior Notes \| 1.50% 20-Year Senior Notes, Due 10/1/2039 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.50%
Term	20 years
Effective interest rate	1.73%
Total borrowings at par value	$ 1,055	932
Senior Notes \| 2.80% 20-Year Senior Notes, Due 10/15/2041
Debt Instrument [Line Items]
Interest rate	2.80%
Term	20 years
Effective interest rate	2.90%
Total borrowings at par value	$ 1,200	1,200
Senior Notes \| 1.625% 20-Year Senior Notes, Due 10/18/2041 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.625%
Term	20 years
Effective interest rate	1.78%
Total borrowings at par value	$ 1,465	1,294
Senior Notes \| 2.069% 20-Year Senior Notes, Due 10/20/2042 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	2.069%
Term	20 years
Effective interest rate	2.13%
Total borrowings at par value	$ 101	93
Senior Notes \| 5.404% 20-Year Senior Notes, Due 8/10/2043
Debt Instrument [Line Items]
Interest rate	5.404%
Term	20 years
Effective interest rate	5.50%
Total borrowings at par value	$ 600	600
Senior Notes \| 2.02% 20-Year Senior Notes, Due 9/6/2043 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	2.02%
Term	20 years
Effective interest rate	2.06%
Total borrowings at par value	$ 200	184
Senior Notes \| 5.30% 30-Year Senior Notes, Due 2/1/2044
Debt Instrument [Line Items]
Interest rate	5.30%
Term	30 years
Effective interest rate	5.37%
Total borrowings at par value	$ 400	400
Senior Notes \| 1.49% 20-Year Senior Notes, Due 1/6/2045 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.49%
Term	20 years
Effective interest rate	1.54%
Total borrowings at par value	$ 232	0
Senior Notes \| 1.8975% 20-Year Senior Notes, Due 3/7/2045 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.8975%
Term	20 years
Effective interest rate	1.95%
Total borrowings at par value	$ 169
Senior Notes \| 4.10% 30-Year Senior Notes, Due 8/15/2047
Debt Instrument [Line Items]
Interest rate	4.10%
Term	30 years
Effective interest rate	4.23%
Total borrowings at par value	$ 750	750
Senior Notes \| 1.875% 30-Year Senior Notes, Due 10/1/2049 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	1.875%
Term	30 years
Effective interest rate	1.99%
Total borrowings at par value	$ 1,172	1,035
Senior Notes \| 1.47% 25-Year Senior Notes, Due 1/6/2050 (Swiss franc-denominated)
Debt Instrument [Line Items]
Interest rate	1.47%
Term	25 years
Effective interest rate	1.49%
Total borrowings at par value	$ 409
Senior Notes \| 2.00% 30-Year Senior Notes, Due 10/18/2051 (euro-denominated)
Debt Instrument [Line Items]
Interest rate	2.00%
Term	30 years
Effective interest rate	2.07%
Total borrowings at par value	$ 879	777
Senior Notes \| 2.382% 30-Year Senior Notes, Due 10/18/2052 (Japanese yen-denominated)
Debt Instrument [Line Items]
Interest rate	2.382%
Term	30 years
Effective interest rate	2.43%
Total borrowings at par value	$ 230	212
Other
Debt Instrument [Line Items]
Total borrowings at par value	1	73
Total borrowings at carrying value	$ 1	$ 73

THERMO FISHER SCIENTIFIC INC. 10-Q