Document and Entity Information (USD $)	3 Months Ended
	Mar. 30, 2013	Jun. 30, 2012
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	Mar. 30, 2013
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 18,917,793,000
Entity Common Stock, Shares Outstanding	358,921,241