Consolidated Statement of Redeemable Noncontrolling Interest and Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock, $1.00 par value	Capital in Excess of Par Value	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Items	Total Thermo Fisher Scientific Inc. Shareholders’ Equity	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2020		437,000,000
Beginning Balance at Dec. 31, 2020	$ 34,517	$ 437	$ 15,579	$ 28,116	$ (6,818)	$ (2,807)	$ 34,507	$ 10
Treasury stock beginning balance (in shares) at Dec. 31, 2020					40,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employees' and directors' stock plans (in shares)		2,000,000			1,000,000
Issuance of shares under employees' and directors' stock plans	137	$ 2	228		$ (93)		137
Stock-based compensation	153		153				153
Purchases of company common stock (in shares)					4,000,000
Purchases of company common stock	(2,000)				$ (2,000)		(2,000)
Dividends declared	(307)			(307)			(307)
Net income	6,069			6,067			6,067	2
Other comprehensive items	153					153	153
Contributions from (distributions to) noncontrolling interests	35							35
Balance (in shares) at Oct. 02, 2021		439,000,000
Treasury stock ending balance (in shares) at Oct. 02, 2021					45,000,000
Ending Balance at Oct. 02, 2021	38,757	$ 439	15,960	33,876	$ (8,911)	(2,654)	38,710	47
Balance (in shares) at Jul. 03, 2021		438,000,000
Beginning Balance at Jul. 03, 2021	36,901	$ 438	15,826	32,076	$ (8,856)	(2,630)	36,854	47
Treasury stock beginning balance (in shares) at Jul. 03, 2021					45,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employees' and directors' stock plans (in shares)		1,000,000			0
Issuance of shares under employees' and directors' stock plans	29	$ 1	83		$ (55)		29
Stock-based compensation	51		51				51
Dividends declared	(102)			(102)			(102)
Net income	1,903			1,902			1,902	1
Other comprehensive items	(24)					(24)	(24)
Contributions from (distributions to) noncontrolling interests	(1)							(1)
Balance (in shares) at Oct. 02, 2021		439,000,000
Treasury stock ending balance (in shares) at Oct. 02, 2021					45,000,000
Ending Balance at Oct. 02, 2021	38,757	$ 439	15,960	33,876	$ (8,911)	(2,654)	38,710	47
Beginning Balance at Dec. 31, 2021	122
Redeemable Noncontrolling Interest [Roll Forward]
Net income	14
Other comprehensive items	(10)
Contributions from (distributions to) noncontrolling interests	(7)
Ending Balance at Oct. 01, 2022	119
Balance (in shares) at Dec. 31, 2021		439,000,000
Beginning Balance at Dec. 31, 2021	$ 40,855	$ 439	16,174	35,431	$ (8,922)	(2,329)	40,793	62
Treasury stock beginning balance (in shares) at Dec. 31, 2021	44,720,112				45,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employees' and directors' stock plans (in shares)		1,000,000			0
Issuance of shares under employees' and directors' stock plans	$ 102	$ 1	190		$ (89)		102
Stock-based compensation	232		232				232
Purchases of company common stock (in shares)					3,000,000
Purchases of company common stock	(2,000)				$ (2,000)		(2,000)
Dividends declared	(353)			(353)			(353)
Net income	5,372			5,374			5,374	(2)
Other comprehensive items	(599)					(599)	(599)
Contributions from (distributions to) noncontrolling interests	$ (1)							(1)
Balance (in shares) at Oct. 01, 2022		440,000,000
Treasury stock ending balance (in shares) at Oct. 01, 2022	48,157,213				48,000,000
Ending Balance at Oct. 01, 2022	$ 43,608	$ 440	16,596	40,452	$ (11,011)	(2,928)	43,549	59
Beginning Balance at Jul. 02, 2022	117
Redeemable Noncontrolling Interest [Roll Forward]
Net income	5
Other comprehensive items	(3)
Ending Balance at Oct. 01, 2022	119
Balance (in shares) at Jul. 02, 2022		440,000,000
Beginning Balance at Jul. 02, 2022	42,354	$ 440	16,467	39,074	$ (10,964)	(2,724)	42,293	61
Treasury stock beginning balance (in shares) at Jul. 02, 2022					48,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employees' and directors' stock plans (in shares)					0
Issuance of shares under employees' and directors' stock plans	5		52		$ (47)		5
Stock-based compensation	77		77				77
Dividends declared	(117)			(117)			(117)
Net income	1,493			1,495			1,495	(2)
Other comprehensive items	$ (204)					(204)	(204)
Balance (in shares) at Oct. 01, 2022		440,000,000
Treasury stock ending balance (in shares) at Oct. 01, 2022	48,157,213				48,000,000
Ending Balance at Oct. 01, 2022	$ 43,608	$ 440	$ 16,596	$ 40,452	$ (11,011)	$ (2,928)	$ 43,549	$ 59