Document and Entity Information - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2015	Jun. 28, 2014
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. 26, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2015
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		$ 47,112,558
Entity Common Stock, Shares Outstanding	399,097,699
Entity Stock Trading Symbol	TMO