Condensed Consolidated Financial Statements (Policies)	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2024 Annual Report on Form 10-K.
Reclassifications	Certain prior period amounts have been reclassified to conform to the current period presentation. Refer to Note 3 for a discussion of the changes in our presentation of disaggregated revenue.
Recent Accounting Pronouncements	Income Tax Disclosures In December 2023, the Financial Accounting Standards Board (“FASB”) issued updated accounting guidance related to income tax disclosures. The updated accounting guidance, among other things, requires additional disclosure primarily related to the income tax rate reconciliation and income taxes paid. We will adopt the updated accounting guidance in our Annual Report on Form 10-K for the year ending December 31, 2025. Disaggregation of Income Statement Expenses In November 2024, the FASB issued updated accounting guidance related to disclosures about certain costs and expenses. The updated accounting guidance, among other things, requires quantitative disclosures for employee compensation, selling expenses and purchases of inventory. The updated guidance is effective beginning in our Annual Report on Form 10-K for the year ending December 31, 2027.
Earnings Per Share	Weighted-average common shares outstanding used in calculating diluted earnings per common share attributable to Comcast Corporation shareholders (“diluted EPS”) considers the impact of potentially dilutive securities using the treasury stock method. Antidilutive securities represent the number of potential common shares related to share-based compensation awards that were excluded from diluted EPS because their effect would have been antidilutive.

Condensed Consolidated Financial Statements (Policies)

6 Months Ended

Jun. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year.

The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2024 Annual Report on Form 10-K.

Reclassifications

Certain prior period amounts have been reclassified to conform to the current period presentation. Refer to Note 3 for a discussion of the changes in our presentation of disaggregated revenue.

Recent Accounting Pronouncements

Income Tax Disclosures

In December 2023, the Financial Accounting Standards Board (“FASB”) issued updated accounting guidance related to income tax disclosures. The updated accounting guidance, among other things, requires additional disclosure primarily related to the income tax rate reconciliation and income taxes paid. We will adopt the updated accounting guidance in our Annual Report on Form 10-K for the year ending December 31, 2025.

Disaggregation of Income Statement Expenses

In November 2024, the FASB issued updated accounting guidance related to disclosures about certain costs and expenses. The updated accounting guidance, among other things, requires quantitative disclosures for employee compensation, selling expenses and purchases of inventory. The updated guidance is effective beginning in our Annual Report on Form 10-K for the year ending December 31, 2027.

Earnings Per Share

Weighted-average common shares outstanding used in calculating diluted earnings per common share attributable to Comcast Corporation shareholders (“diluted EPS”) considers the impact of potentially dilutive securities using the treasury stock method. Antidilutive securities represent the number of potential common shares related to share-based compensation awards that were excluded from diluted EPS because their effect would have been antidilutive.