Financing Commitments (Details) (Life Technologies Corporation [Member], USD $) In Billions, unless otherwise specified			9 Months Ended
Sep. 28, 2013 Unsecured 3-year Term Loan Facility	Nov. 01, 2013 364-day Unsecured Bridge Financing	Sep. 28, 2013 364-day Unsecured Bridge Financing Unsecured 3-year Term Loan Facility
Short-term Financing [Line Items]
Maximum Borrowing Capacity	$ 5.00	$ 3.56
Debt, Covenant, Maximum Consolidated Total Leverage Ratio of Debt to EBITDA First Six Months			5.5
Debt, Covenant, Maximum Consolidated Total Leverage Ratio Of Debt To EBITDA After Eighteen Months			3.5
Debt, Covenant, Minimum Consolidated Interest Coverage Ratio			3.0

Maximum permitted Consolidated Leverage Ratio (the ratio of Indebtedness to Consolidated EBITDA) as defined in the debt or line of credit facility agreements for the period beginning eighteen months after the closing of the Life Technologies acquisition.

No definition available.

+ Details

Name:	tmo_DebtCovenantMaximumConsolidatedTotalLeverageRatioOfDebtToEbitdaAfterEighteenMonths
Namespace Prefix:	tmo_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum permitted Consolidated Leverage Ratio (the ratio of Indebtedness to Consolidated EBITDA) as defined in the debt or line of credit facility agreements for the period from the closing of the Life Technologies acquisition until a date six months later.

+ References

No definition available.

+ Details

Name:	tmo_DebtCovenantMaximumConsolidatedTotalLeverageRatioOfDebtToEbitdaFirstSixMonths
Namespace Prefix:	tmo_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum permitted Consolidated Interest Coverage Ratio (the ratio of Consolidated EBITDA to Consolidated Interest Expense) as defined in the debt or line of credit facility agreements.

+ References

No definition available.

+ Details

Name:	tmo_DebtCovenantMinimumConsolidatedInterestCoverageRatio
Namespace Prefix:	tmo_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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