Debt Senior Notes (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended
Feb. 22, 2011	Jul. 02, 2011
Debt Issuance [Line Items]
Face Amount Issued	$ 2,200
2.05% Senior Notes due 2014 [Member]
Debt Issuance [Line Items]
Face Amount Issued	300
Debt Instrument, Interest Rate, Stated Percentage	2.05%
Debt Instrument, Description of Variable Rate Basis	six-month USD LIBOR
Notional Amount of Interest Rate Swap	300
Interest Rate Swap, Basis Spread On Variable Rate		0.4112%
Interest Rate Swap, Variable Interest Rate		0.88%
Interest Rate Swap, Fixed Interest Rate		2.05%
3.20% Senior Notes due 2016 [Member]
Debt Issuance [Line Items]
Face Amount Issued	900
Debt Instrument, Interest Rate, Stated Percentage	3.20%
4.50% Senior Notes due 2021 [Member]
Debt Issuance [Line Items]
Face Amount Issued	$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	4.50%

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ Details

Name:	tmo_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix:	tmo
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest rate stated in the contractual debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

+ Details

Name:	us-gaap_DerivativeBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

+ Details

Name:	us-gaap_DerivativeVariableInterestRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate notional amount of interest rate derivatives, which relates to the currency amount specified in the interest rate derivative instruments.

+ Details

Name:	us-gaap_NotionalAmountOfInterestRateDerivatives
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant