XML 144 R130.htm IDEA: XBRL DOCUMENT
v3.20.4

Impairment, Restructuring Charges and Other Related Closure Costs - Summary of Impairment, Restructuring Charges and Other Related Closure Costs (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Restructuring Cost And Reserve [Line Items] |  |  |
Impairment | $ (4) | $ (7) | $ (2)
Restructuring charges | (7) | 2 | (19)
Total impairment, restructuring charges and other related closure costs | (11) | (5) | (21)
Set-top Box Restructuring Plan [Member] |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |
Restructuring charges | 1 | 2 | (19)
Total impairment, restructuring charges and other related closure costs | 1 | 2 | (19)
Long-lived Asset Impairment Charge [Member] |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |
Impairment | (4) | (7) | (2)
Total impairment, restructuring charges and other related closure costs | (4) | $ (7) | $ (2)
Bouskoura Restructuring Plan [Member] |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |
Restructuring charges | (8) |  |
Total impairment, restructuring charges and other related closure costs | $ (8) |  |

X
- Definition Severance costs credits. + References No definition available. + Details
Name: | stm_SeveranceCostsCredits
Namespace Prefix: | stm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
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_RestructuringCostAndReserveLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of restructuring charges, remediation cost, and asset impairment loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_RestructuringSettlementAndImpairmentProvisions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_RestructuringPlanAxis=stm_SetTopBoxRestructuringPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=stm_LongLivedAssetChargesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=stm_BouskouraRestructuringPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |