XML 38 R28.htm IDEA: XBRL DOCUMENT v3.24.1.u1

Segment Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 segment business
Segment Reporting Information [Line Items]
Number of primary businesses | business	2
Connectivity & Platforms
Segment Reporting Information [Line Items]
Number of reportable segments	2
Content & Experiences
Segment Reporting Information [Line Items]
Number of reportable segments	3

X

- Definition

Number Of Businesses

+ References

No definition available.

+ Details

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Namespace Prefix:	cmcsa_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-18

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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X

- Details

Name:	cmcsa_BusinessUnitAxis=cmcsa_ConnectivityAndPlatformsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: