v3.5.0.2
Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Service revenue $ 19,269 $ 18,743 $ 38,059 $ 36,596
Management fee revenue 0 0 0 0
Revenue 19,269 18,743 38,059 36,596
Costs and Expenses:        
Programming and production 5,492 5,669 10,923 11,132
Other operating and administrative 5,761 5,274 11,286 10,348
Advertising, marketing and promotion 1,561 1,534 3,028 2,894
Depreciation 1,868 1,674 3,653 3,308
Amortization 521 487 1,014 919
Costs and expenses, total 15,203 14,638 29,904 28,601
Operating income (loss) 4,066 4,105 8,155 7,995
Other Income (Expense):        
Interest expense (732) (713) (1,435) (1,369)
Investment income (loss), net 58 17 88 50
Equity in net income (losses) of investees, net (19) (236) (30) (203)
Other income (expense), net (15) 315 115 417
Nonoperating income (Expense), Total (708) (617) (1,262) (1,105)
Income (loss) before income taxes 3,358 3,488 6,893 6,890
Income tax (expense) benefit (1,278) (1,313) (2,589) (2,574)
Net income (loss) 2,080 2,175 4,304 4,316
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock (52) (38) (142) (120)
Net income (loss) attributable to Parent 2,028 2,137 4,162 4,196
Comprehensive income attributable to Parent 2,113 2,159 4,337 4,176
Elimination and Consolidation Adjustments [Member]        
Service revenue 0 0 0 0
Management fee revenue (527) (498) (1,040) (979)
Revenue (527) (498) (1,040) (979)
Costs and Expenses:        
Programming and production 0 0 0 0
Other operating and administrative (527) (498) (1,040) (979)
Advertising, marketing and promotion 0 0 0 0
Depreciation 0 0 0 0
Amortization 0 0 0 0
Costs and expenses, total (527) (498) (1,040) (979)
Operating income (loss) 0 0 0 0
Other Income (Expense):        
Interest expense 0 0 0 0
Investment income (loss), net 0 0 0 0
Equity in net income (losses) of investees, net (8,977) (8,806) (18,020) (17,429)
Other income (expense), net 0 0 0 0
Nonoperating income (Expense), Total (8,977) (8,806) (18,020) (17,429)
Income (loss) before income taxes (8,977) (8,806) (18,020) (17,429)
Income tax (expense) benefit 0 0 0 0
Net income (loss) (8,977) (8,806) (18,020) (17,429)
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0 0 0
Net income (loss) attributable to Parent (8,977) (8,806) (18,020) (17,429)
Comprehensive income attributable to Parent (9,698) (8,838) (18,933) (17,391)
Comcast Parent [Member]        
Service revenue 0 0 0 0
Management fee revenue 266 252 525 496
Revenue 266 252 525 496
Costs and Expenses:        
Programming and production 0 0 0 0
Other operating and administrative 285 225 441 451
Advertising, marketing and promotion 0 0 0 0
Depreciation 6 7 14 15
Amortization 2 2 3 3
Costs and expenses, total 293 234 458 469
Operating income (loss) (27) 18 67 27
Other Income (Expense):        
Interest expense (478) (472) (929) (882)
Investment income (loss), net 3 0 3 1
Equity in net income (losses) of investees, net 2,354 2,431 4,720 4,753
Other income (expense), net 0 2 0 (3)
Nonoperating income (Expense), Total 1,879 1,961 3,794 3,869
Income (loss) before income taxes 1,852 1,979 3,861 3,896
Income tax (expense) benefit 176 158 301 300
Net income (loss) 2,028 2,137 4,162 4,196
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0 0 0
Net income (loss) attributable to Parent 2,028 2,137 4,162 4,196
Comprehensive income attributable to Parent 2,113 2,159 4,337 4,176
Comcast Holdings [Member]        
Service revenue 0 0 0 0
Management fee revenue 0 0 0 0
Revenue 0 0 0 0
Costs and Expenses:        
Programming and production 0 0 0 0
Other operating and administrative 0 0 0 0
Advertising, marketing and promotion 0 0 0 0
Depreciation 0 0 0 0
Amortization 0 0 0 0
Costs and expenses, total 0 0 0 0
Operating income (loss) 0 0 0 0
Other Income (Expense):        
Interest expense (3) (3) (6) (6)
Investment income (loss), net 1 (1) 1 1
Equity in net income (losses) of investees, net 2,275 2,162 4,539 4,388
Other income (expense), net 0 0 0 0
Nonoperating income (Expense), Total 2,273 2,158 4,534 4,383
Income (loss) before income taxes 2,273 2,158 4,534 4,383
Income tax (expense) benefit 1 2 2 2
Net income (loss) 2,274 2,160 4,536 4,385
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0 0 0
Net income (loss) attributable to Parent 2,274 2,160 4,536 4,385
Comprehensive income attributable to Parent 2,321 2,168 4,627 4,377
CCCL Parent [Member]        
Service revenue 0 0 0 0
Management fee revenue 261 246 515 483
Revenue 261 246 515 483
Costs and Expenses:        
Programming and production 0 0 0 0
Other operating and administrative 261 246 515 483
Advertising, marketing and promotion 0 0 0 0
Depreciation 0 0 0 0
Amortization 0 0 0 0
Costs and expenses, total 261 246 515 483
Operating income (loss) 0 0 0 0
Other Income (Expense):        
Interest expense (61) (73) (120) (146)
Investment income (loss), net 0 0 0 0
Equity in net income (losses) of investees, net 2,127 2,020 4,241 4,012
Other income (expense), net 0 0 0 0
Nonoperating income (Expense), Total 2,066 1,947 4,121 3,866
Income (loss) before income taxes 2,066 1,947 4,121 3,866
Income tax (expense) benefit 21 26 42 51
Net income (loss) 2,087 1,973 4,163 3,917
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0 0 0
Net income (loss) attributable to Parent 2,087 1,973 4,163 3,917
Comprehensive income attributable to Parent 2,087 1,973 4,165 3,915
NBCUniversal Media Parent [Member]        
Service revenue 0 0 0 0
Management fee revenue 0 0 0 0
Revenue 0 0 0 0
Costs and Expenses:        
Programming and production 0 0 0 0
Other operating and administrative 222 255 517 492
Advertising, marketing and promotion 0 0 0 0
Depreciation 0 0 0 0
Amortization 0 0 0 0
Costs and expenses, total 222 255 517 492
Operating income (loss) (222) (255) (517) (492)
Other Income (Expense):        
Interest expense (112) (116) (229) (236)
Investment income (loss), net (6) (8) (8) (14)
Equity in net income (losses) of investees, net 1,288 1,281 2,585 2,512
Other income (expense), net (7) 16 117 5
Nonoperating income (Expense), Total 1,163 1,173 2,465 2,267
Income (loss) before income taxes 941 918 1,948 1,775
Income tax (expense) benefit (8) (6) (13) (11)
Net income (loss) 933 912 1,935 1,764
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0 0 0
Net income (loss) attributable to Parent 933 912 1,935 1,764
Comprehensive income attributable to Parent 1,096 936 2,242 1,737
Comcast Non-Guarantor Subsidiaries [Member]        
Service revenue 19,269 18,743 38,059 36,596
Management fee revenue 0 0 0 0
Revenue 19,269 18,743 38,059 36,596
Costs and Expenses:        
Programming and production 5,492 5,669 10,923 11,132
Other operating and administrative 5,520 5,046 10,853 9,901
Advertising, marketing and promotion 1,561 1,534 3,028 2,894
Depreciation 1,862 1,667 3,639 3,293
Amortization 519 485 1,011 916
Costs and expenses, total 14,954 14,401 29,454 28,136
Operating income (loss) 4,315 4,342 8,605 8,460
Other Income (Expense):        
Interest expense (78) (49) (151) (99)
Investment income (loss), net 60 26 92 62
Equity in net income (losses) of investees, net 914 676 1,905 1,561
Other income (expense), net (8) 297 (2) 415
Nonoperating income (Expense), Total 888 950 1,844 1,939
Income (loss) before income taxes 5,203 5,292 10,449 10,399
Income tax (expense) benefit (1,468) (1,493) (2,921) (2,916)
Net income (loss) 3,735 3,799 7,528 7,483
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock (52) (38) (142) (120)
Net income (loss) attributable to Parent 3,683 3,761 7,386 7,363
Comprehensive income attributable to Parent $ 4,194 $ 3,761 $ 7,899 $ 7,362