Upper limit of directors and officers insurance coverage relating to loss contingency.

No definition available.

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Namespace Prefix:	mrk_
Data Type:	xbrli:monetaryItemType
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- Definition

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

Name:	us-gaap_LitigationCaseAxis=mrk_VioxxSecuritiesLawsuitMember
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Contingencies and Environmental Liabilities - Vioxx Litigation - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 legalmatter	Feb. 28, 2015 legalmatter
Vioxx MDL Litigation [Member] \| Vioxx [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	25
Cases alleging economic loss [Member] \| Vioxx [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	30
Litigation settlement agreement amount	$ 23,000,000
Vioxx Cases Brought by State Attorneys General [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	3
Vioxx Securities Lawsuits [Member]
Loss Contingencies [Line Items]
Upper limit of Directors and Officers insurance coverage	145,000,000
Vioxx Securities Lawsuits [Member] \| Subsequent Event [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number		6
Vioxx Canadian Litigation [Member] \| Minimum [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	21,000,000
Vioxx Canadian Litigation [Member] \| Maximum [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 36,000,000