XML 165 R151.htm IDEA: XBRL DOCUMENT v3.20.4

Financial Instruments and Risk Management - Schedule of Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Detail) - Fair Value, Inputs, Level 3 [Member] $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration on business combinations	$ 117
Changes in fair value measurement	1
Currency translation adjustment	5
December 31, 2020	123
Amount of total losses for the period included in earnings attributable to liabilities still held at the reporting date	$ 1

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis liabilities still held gain loss included in earnings at reporting date.

+ References

No definition available.

+ Details

Name:	stm_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitiesStillHeldGainLossIncludedInEarningsAtReportingDate
Namespace Prefix:	stm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis liability currency translation adjustment.

+ References

No definition available.

+ Details

Name:	stm_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityCurrencyTranslationAdjustment
Namespace Prefix:	stm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Fair value measurement with unobservable inputs reconciliations recurring basis business combination contingent consideration.

+ References

No definition available.

+ Details

Name:	stm_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisBusinessCombinationContingentConsideration
Namespace Prefix:	stm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

X

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: