Document and Entity Information (USD $)	9 Months Ended
	Sep. 29, 2012	Jul. 02, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	Thermo Fisher Scientific Inc.
Entity Central Index Key	0000097745
Document Type	10-Q
Document Period End Date	Sep. 29, 2012
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 24,767,287,000
Entity Common Stock, Shares Outstanding	360,214,897