v3.25.2
Document and Entity Information
Jun. 18, 2025
Document Information [Line Items]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jun. 18, 2025
Entity Registrant Name Comcast Corporation
Entity Central Index Key 0001166691
Entity Incorporation, State or Country Code PA
Entity File Number 001-32871
Entity Tax Identification Number 27-0000798
Entity Address, Address Line One One Comcast Center
Entity Address, City or Town Philadelphia
Entity Address, State or Province PA
Entity Address, Postal Zip Code 19103-2838
City Area Code 215
Local Phone Number 286-1700
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Class A Common Stock [Member]  
Document Information [Line Items]  
Title of 12(b) Security Class A Common Stock, $0.01 par value
Trading Symbol CMCSA
Security Exchange Name NASDAQ
0.250% Notes Due 2027 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 0.250% Notes due 2027
Trading Symbol CMCS27
Security Exchange Name NASDAQ
1.500% Notes Due 2029 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 1.500% Notes due 2029
Trading Symbol CMCS29
Security Exchange Name NASDAQ
0.750% Notes Due 2032 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 0.750% Notes due 2032
Trading Symbol CMCS32
Security Exchange Name NASDAQ
1.875% Notes Due 2036 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 1.875% Notes due 2036
Trading Symbol CMCS36
Security Exchange Name NASDAQ
1.250% Notes Due 2040 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 1.250% Notes due 2040
Trading Symbol CMCS40
Security Exchange Name NASDAQ
5.50% Notes Due 2029 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 5.50% Notes due 2029
Trading Symbol CCGBP29
Security Exchange Name NYSE
2.0% Exchangeable Subordinated Debentures Due 2029 [Member]  
Document Information [Line Items]  
Title of 12(b) Security 2.0% Exchangeable Subordinated Debentures due 2029
Trading Symbol CCZ
Security Exchange Name NYSE
Notes 0.000 percent Due 2026  
Document Information [Line Items]  
Title of 12(b) Security 0.000% Notes due 2026
Trading Symbol CMCS26
Security Exchange Name NASDAQ
Notes 0.0250 percent Due 2029  
Document Information [Line Items]  
Title of 12(b) Security 0.250% Notes due 2029
Trading Symbol CMCS29A
Security Exchange Name NASDAQ
Notes 3.250 percent due 2032  
Document Information [Line Items]  
Title of 12(b) Security 3.250% Notes due 2032
Trading Symbol CMCS32A
Security Exchange Name NASDAQ
Notes 3.550 percent due 2036  
Document Information [Line Items]  
Title of 12(b) Security 3.550% Notes due 2036
Trading Symbol CMCS36A
Security Exchange Name NASDAQ
Notes 5.250 percent due 2040  
Document Information [Line Items]  
Title of 12(b) Security 5.250% Notes due 2040
Trading Symbol CMCS40A
Security Exchange Name NASDAQ