v3.10.0.1
Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheet) (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Assets        
Cash and cash equivalents $ 3,814 $ 3,428    
Receivables, net 11,104 8,834    
Programming rights 3,746 1,613    
Other current assets 3,184 2,468    
Total current assets 21,848 16,343    
Film and television costs 7,837 7,087    
Investments 7,883 6,931    
Investments in and amounts due from subsidiaries eliminated upon consolidation 0 0    
Property and equipment, net 44,437 38,470    
Franchise rights 59,365 59,364    
Goodwill 66,154 36,780 $ 35,980  
Other intangible assets, net 38,358 18,133    
Other noncurrent assets, net 5,802 4,354    
Total assets 251,684 187,462    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 8,494 6,908    
Accrued participations and residuals 1,808 1,644    
Deferred revenue 2,182 1,687    
Accrued expenses and other current liabilities 10,721 6,620    
Current portion of long-term debt 4,398 5,134    
Total current liabilities 27,603 21,993    
Long-term debt, less current portion 107,345 59,422    
Deferred income taxes 27,589 24,259    
Other noncurrent liabilities 15,329 10,972    
Redeemable noncontrolling interests 1,316 1,357    
Equity:        
Common stock 54 55    
Other shareholders’ equity 71,559 68,561    
Total Comcast Corporation shareholders’ equity 71,613 68,616    
Noncontrolling interests 889 843    
Total equity 72,502 69,459 $ 56,163 $ 53,978
Total liabilities and equity 251,684 187,462    
Elimination and Consolidation Adjustments [Member]        
Assets        
Cash and cash equivalents 0 0    
Receivables, net 0 0    
Programming rights 0 0    
Other current assets 0 0    
Total current assets 0 0    
Film and television costs 0 0    
Investments 0 0    
Investments in and amounts due from subsidiaries eliminated upon consolidation (586,231) (562,645)    
Property and equipment, net 0 0    
Franchise rights 0 0    
Goodwill 0 0    
Other intangible assets, net 0 0    
Other noncurrent assets, net (458) (314)    
Total assets (586,689) (562,959)    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 0 0    
Accrued participations and residuals 0 0    
Deferred revenue 0 0    
Accrued expenses and other current liabilities 0 0    
Current portion of long-term debt 0 0    
Total current liabilities 0 0    
Long-term debt, less current portion 0 0    
Deferred income taxes (524) (343)    
Other noncurrent liabilities 66 29    
Redeemable noncontrolling interests 0 0    
Equity:        
Common stock 0 0    
Other shareholders’ equity (586,231) (562,645)    
Total Comcast Corporation shareholders’ equity (586,231) (562,645)    
Noncontrolling interests 0 0    
Total equity (586,231) (562,645)    
Total liabilities and equity (586,689) (562,959)    
Comcast Parent [Member] | Reportable Legal Entities [Member]        
Assets        
Cash and cash equivalents 0 0    
Receivables, net 0 0    
Programming rights 0 0    
Other current assets 66 60    
Total current assets 66 60    
Film and television costs 0 0    
Investments 270 146    
Investments in and amounts due from subsidiaries eliminated upon consolidation 157,264 117,164    
Property and equipment, net 670 551    
Franchise rights 0 0    
Goodwill 0 0    
Other intangible assets, net 11 12    
Other noncurrent assets, net 1,057 435    
Total assets 159,338 118,368    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 2 16    
Accrued participations and residuals 0 0    
Deferred revenue 0 0    
Accrued expenses and other current liabilities 2,357 1,888    
Current portion of long-term debt 699 2,810    
Total current liabilities 3,058 4,714    
Long-term debt, less current portion 81,661 42,428    
Deferred income taxes 0 0    
Other noncurrent liabilities 3,006 2,610    
Redeemable noncontrolling interests 0 0    
Equity:        
Common stock 54 55    
Other shareholders’ equity 71,559 68,561    
Total Comcast Corporation shareholders’ equity 71,613 68,616    
Noncontrolling interests 0 0    
Total equity 71,613 68,616    
Total liabilities and equity 159,338 118,368    
Subsidiary Issuer [Member] | Reportable Legal Entities [Member] | Comcast Holdings [Member]        
Assets        
Cash and cash equivalents 0 0    
Receivables, net 0 0    
Programming rights 0 0    
Other current assets 20 0    
Total current assets 20 0    
Film and television costs 0 0    
Investments 11 21    
Investments in and amounts due from subsidiaries eliminated upon consolidation 147,028 142,519    
Property and equipment, net 0 0    
Franchise rights 0 0    
Goodwill 0 0    
Other intangible assets, net 0 0    
Other noncurrent assets, net 208 708    
Total assets 147,267 143,248    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 0 0    
Accrued participations and residuals 0 0    
Deferred revenue 0 0    
Accrued expenses and other current liabilities 150 92    
Current portion of long-term debt 0 0    
Total current liabilities 150 92    
Long-term debt, less current portion 146 140    
Deferred income taxes 314 285    
Other noncurrent liabilities 0 0    
Redeemable noncontrolling interests 0 0    
Equity:        
Common stock 0 0    
Other shareholders’ equity 146,657 142,731    
Total Comcast Corporation shareholders’ equity 146,657 142,731    
Noncontrolling interests 0 0    
Total equity 146,657 142,731    
Total liabilities and equity 147,267 143,248    
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member] | CCCL Parent [Member]        
Assets        
Cash and cash equivalents 0 0    
Receivables, net 0 0    
Programming rights 0 0    
Other current assets 0 7    
Total current assets 0 7    
Film and television costs 0 0    
Investments 143 108    
Investments in and amounts due from subsidiaries eliminated upon consolidation 130,214 139,528    
Property and equipment, net 0 0    
Franchise rights 0 0    
Goodwill 0 0    
Other intangible assets, net 0 0    
Other noncurrent assets, net 0 0    
Total assets 130,357 139,643    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 0 0    
Accrued participations and residuals 0 0    
Deferred revenue 0 0    
Accrued expenses and other current liabilities 360 333    
Current portion of long-term debt 0 0    
Total current liabilities 360 333    
Long-term debt, less current portion 2,100 2,100    
Deferred income taxes 0 0    
Other noncurrent liabilities 0 0    
Redeemable noncontrolling interests 0 0    
Equity:        
Common stock 0 0    
Other shareholders’ equity 127,897 137,210    
Total Comcast Corporation shareholders’ equity 127,897 137,210    
Noncontrolling interests 0 0    
Total equity 127,897 137,210    
Total liabilities and equity 130,357 139,643    
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member] | NBCUniversal Media Parent [Member]        
Assets        
Cash and cash equivalents 416 496    
Receivables, net 0 0    
Programming rights 0 0    
Other current assets 28 25    
Total current assets 444 521    
Film and television costs 0 0    
Investments 790 693    
Investments in and amounts due from subsidiaries eliminated upon consolidation 53,853 50,102    
Property and equipment, net 0 0    
Franchise rights 0 0    
Goodwill 0 0    
Other intangible assets, net 0 0    
Other noncurrent assets, net 85 88    
Total assets 55,172 51,404    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 0 0    
Accrued participations and residuals 0 0    
Deferred revenue 0 0    
Accrued expenses and other current liabilities 282 326    
Current portion of long-term debt 4 4    
Total current liabilities 286 330    
Long-term debt, less current portion 7,748 7,751    
Deferred income taxes 65 67    
Other noncurrent liabilities 1,201 1,128    
Redeemable noncontrolling interests 0 0    
Equity:        
Common stock 0 0    
Other shareholders’ equity 45,872 42,128    
Total Comcast Corporation shareholders’ equity 45,872 42,128    
Noncontrolling interests 0 0    
Total equity 45,872 42,128    
Total liabilities and equity 55,172 51,404    
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]        
Assets        
Cash and cash equivalents 3,398 2,932    
Receivables, net 11,104 8,834    
Programming rights 3,746 1,613    
Other current assets 3,070 2,376    
Total current assets 21,318 15,755    
Film and television costs 7,837 7,087    
Investments 6,669 5,963    
Investments in and amounts due from subsidiaries eliminated upon consolidation 97,872 113,332    
Property and equipment, net 43,767 37,919    
Franchise rights 59,365 59,364    
Goodwill 66,154 36,780    
Other intangible assets, net 38,347 18,121    
Other noncurrent assets, net 4,910 3,437    
Total assets 346,239 297,758    
Liabilities and Equity        
Accounts payable and accrued expenses related to trade creditors 8,492 6,892    
Accrued participations and residuals 1,808 1,644    
Deferred revenue 2,182 1,687    
Accrued expenses and other current liabilities 7,572 3,981    
Current portion of long-term debt 3,695 2,320    
Total current liabilities 23,749 16,524    
Long-term debt, less current portion 15,690 7,003    
Deferred income taxes 27,734 24,250    
Other noncurrent liabilities 11,056 7,205    
Redeemable noncontrolling interests 1,316 1,357    
Equity:        
Common stock 0 0    
Other shareholders’ equity 265,805 240,576    
Total Comcast Corporation shareholders’ equity 265,805 240,576    
Noncontrolling interests 889 843    
Total equity 266,694 241,419    
Total liabilities and equity $ 346,239 $ 297,758