v3.7.0.1

Earnings Per Share (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2017
Earnings Per Share [Abstract] |
Computation of diluted EPS | Computation of Diluted EPS
| Three Months Ended March 31
| 2017 | 2016
(in millions, except per share amounts) | Net Income Attributable to Comcast Corporation | Shares | Per Share Amount | Net Income Attributable to Comcast Corporation | Shares | Per Share Amount
Basic EPS attributable to Comcast Corporation shareholders | $ | 2,566 |  | 4,747 |  | $ | 0.54 |  | $ | 2,134 |  | 4,868 |  | $ | 0.44 |
Effect of dilutive securities: |  |  |  |  |  |
Assumed exercise or issuance of shares relating to stock plans |  | 85 |  |  |  | 57 |  |
Diluted EPS attributable to Comcast Corporation shareholders | $ | 2,566 |  | 4,832 |  | $ | 0.53 |  | $ | 2,134 |  | 4,925 |  | $ | 0.43 |

X
- References No definition available. + Details
Name: | us-gaap_EarningsPerShareAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration