v3.7.0.1
Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Revenue:    
Service revenue $ 20,463 $ 18,790
Management fee revenue 0 0
Revenue 20,463 18,790
Costs and Expenses:    
Programming and production 6,074 5,431
Other operating and administrative 5,827 5,526
Advertising, marketing and promotion 1,530 1,466
Depreciation 1,915 1,785
Amortization 587 493
Costs and expenses, total 15,933 14,701
Operating income (loss) 4,530 4,089
Other Income (Expense):    
Interest expense (755) (703)
Investment income (loss), net 59 30
Equity in net income (losses) of investees, net 36 (11)
Other income (expense), net 35 130
Other income (expense) items, net (625) (554)
Income (loss) before income taxes 3,905 3,535
Income tax (expense) benefit (1,258) (1,311)
Net income (loss) 2,647 2,224
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock (81) (90)
Net income (loss) attributable to Parent 2,566 2,134
Comprehensive income attributable to Parent 2,810 2,224
Elimination and Consolidation Adjustments [Member]    
Revenue:    
Service revenue 0 0
Management fee revenue (545) (513)
Revenue (545) (513)
Costs and Expenses:    
Programming and production 0 0
Other operating and administrative (545) (513)
Advertising, marketing and promotion 0 0
Depreciation 0 0
Amortization 0 0
Costs and expenses, total (545) (513)
Operating income (loss) 0 0
Other Income (Expense):    
Interest expense 0 0
Investment income (loss), net 0 0
Equity in net income (losses) of investees, net (10,606) (9,043)
Other income (expense), net 0 0
Other income (expense) items, net (10,606) (9,043)
Income (loss) before income taxes (10,606) (9,043)
Income tax (expense) benefit 0 0
Net income (loss) (10,606) (9,043)
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0
Net income (loss) attributable to Parent (10,606) (9,043)
Comprehensive income attributable to Parent (11,107) (9,235)
Comcast Parent [Member]    
Revenue:    
Service revenue 0 0
Management fee revenue 275 259
Revenue 275 259
Costs and Expenses:    
Programming and production 0 0
Other operating and administrative 170 156
Advertising, marketing and promotion 0 0
Depreciation 7 8
Amortization 2 1
Costs and expenses, total 179 165
Operating income (loss) 96 94
Other Income (Expense):    
Interest expense (517) (451)
Investment income (loss), net 1 0
Equity in net income (losses) of investees, net 2,839 2,366
Other income (expense), net 0 0
Other income (expense) items, net 2,323 1,915
Income (loss) before income taxes 2,419 2,009
Income tax (expense) benefit 147 125
Net income (loss) 2,566 2,134
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0
Net income (loss) attributable to Parent 2,566 2,134
Comprehensive income attributable to Parent 2,810 2,224
Comcast Holdings [Member]    
Revenue:    
Service revenue 0 0
Management fee revenue 0 0
Revenue 0 0
Costs and Expenses:    
Programming and production 0 0
Other operating and administrative 0 0
Advertising, marketing and promotion 0 0
Depreciation 0 0
Amortization 0 0
Costs and expenses, total 0 0
Operating income (loss) 0 0
Other Income (Expense):    
Interest expense (3) (3)
Investment income (loss), net 28 0
Equity in net income (losses) of investees, net 2,650 2,264
Other income (expense), net 0 0
Other income (expense) items, net 2,675 2,261
Income (loss) before income taxes 2,675 2,261
Income tax (expense) benefit (9) 1
Net income (loss) 2,666 2,262
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0
Net income (loss) attributable to Parent 2,666 2,262
Comprehensive income attributable to Parent 2,716 2,306
CCCL Parent [Member]    
Revenue:    
Service revenue 0 0
Management fee revenue 270 254
Revenue 270 254
Costs and Expenses:    
Programming and production 0 0
Other operating and administrative 270 254
Advertising, marketing and promotion 0 0
Depreciation 0 0
Amortization 0 0
Costs and expenses, total 270 254
Operating income (loss) 0 0
Other Income (Expense):    
Interest expense (60) (59)
Investment income (loss), net 0 0
Equity in net income (losses) of investees, net 2,320 2,114
Other income (expense), net 0 0
Other income (expense) items, net 2,260 2,055
Income (loss) before income taxes 2,260 2,055
Income tax (expense) benefit 21 21
Net income (loss) 2,281 2,076
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0
Net income (loss) attributable to Parent 2,281 2,076
Comprehensive income attributable to Parent 2,282 2,078
NBCUniversal Media Parent [Member]    
Revenue:    
Service revenue 0 0
Management fee revenue 0 0
Revenue 0 0
Costs and Expenses:    
Programming and production 0 0
Other operating and administrative 306 295
Advertising, marketing and promotion 0 0
Depreciation 0 0
Amortization 0 0
Costs and expenses, total 306 295
Operating income (loss) (306) (295)
Other Income (Expense):    
Interest expense (112) (117)
Investment income (loss), net (4) (2)
Equity in net income (losses) of investees, net 1,597 1,297
Other income (expense), net 28 124
Other income (expense) items, net 1,509 1,302
Income (loss) before income taxes 1,203 1,007
Income tax (expense) benefit (3) (5)
Net income (loss) 1,200 1,002
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock 0 0
Net income (loss) attributable to Parent 1,200 1,002
Comprehensive income attributable to Parent 1,406 1,146
Comcast Non-Guarantor Subsidiaries [Member]    
Revenue:    
Service revenue 20,463 18,790
Management fee revenue 0 0
Revenue 20,463 18,790
Costs and Expenses:    
Programming and production 6,074 5,431
Other operating and administrative 5,626 5,334
Advertising, marketing and promotion 1,530 1,466
Depreciation 1,908 1,777
Amortization 585 492
Costs and expenses, total 15,723 14,500
Operating income (loss) 4,740 4,290
Other Income (Expense):    
Interest expense (63) (73)
Investment income (loss), net 34 32
Equity in net income (losses) of investees, net 1,236 991
Other income (expense), net 7 6
Other income (expense) items, net 1,214 956
Income (loss) before income taxes 5,954 5,246
Income tax (expense) benefit (1,414) (1,453)
Net income (loss) 4,540 3,793
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock (81) (90)
Net income (loss) attributable to Parent 4,459 3,703
Comprehensive income attributable to Parent $ 4,703 $ 3,705