XML 118 R78.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Contingencies and Environmental Liabilities - Environmental Litigation and Matters - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Site Contingency [Line Items]
Accrued liabilities for environmental matters	$ 67	$ 71
Term for paying off environmental liabilities	15 years
Aggregate possible expenditure on environmental matters in excess of amounts accrued	$ 58

X

- Definition

Term for paying off environmental liabilities.

+ References

No definition available.

+ Details

Name:	mrk_TermForPayingOffEnvironmentalLiabilities
Namespace Prefix:	mrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Total costs accrued as of the balance sheet date for environmental loss contingencies.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

+ Details

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

X

- Definition

Estimate of reasonably possible loss exposure in excess of amount accrued for remediation, site restoration, postclosure, monitoring commitments, or other exit costs associated with the sale, disposal or abandonment of a particular property resulting from unanticipated contamination of the assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 5.Y.Q4)
-URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14394-108349

+ Details

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

X

- 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.

+ References

No definition available.

+ Details

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