Name:	tmo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentContingentConsideration
Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to contract liabilities assumed in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	tmo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentContractLiabilities
Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to equity method investments acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	tmo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentEquityMethodInvestments
Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to other current assets acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	tmo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAssets
Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to other liabilities assumed in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	tmo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities
Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

Name:	us-gaap_BusinessCombinationAndAssetAcquisitionAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of increase (decrease) to assets, excluding financial assets and goodwill, lacking physical substance with a finite life for purchase accounting adjustments.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetsPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
-URI https://asc.fasb.org/extlink&oid=123586518&loc=d3e961-128460