Additional Financial Information (Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Consolidated assets of variable interest entity	$ 236	$ 236	$ 236
Acquisition price of interest in variable interest entity		94
Payments to acquire interest in variable interest entity	$ 40

Variable Interest Entity, Acquisition Price, Outstanding Interest

No definition available.

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Namespace Prefix:	tmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

The cash outflow associated with the purchase of noncontrolling interest during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

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Period Type:	duration

- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5710-111685

+ Details

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Balance Type:	debit
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- Details

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