v2.4.0.8
Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Service revenue                 $ 64,657 $ 62,570 $ 55,842
Revenue 16,926 16,151 16,270 15,310 15,937 16,544 15,211 14,878 64,657 62,570 55,842
Programming and production                 19,670 19,929 16,596
Other operating and administrative                 18,584 17,833 16,646
Advertising, marketing and promotion                 4,969 4,831 4,243
Depreciation                 6,254 6,150 6,040
Amortization                 1,617 1,648 1,596
Costs and expenses, total                 51,094 50,391 45,121
Operating income (loss) 3,647 3,414 3,435 3,067 3,294 3,048 3,079 2,758 13,563 12,179 10,721
Interest expense                 (2,574) (2,521) (2,505)
Investment income (loss), net                 576 219 159
Equity in net income (losses) of investees, net                 (86) 959 (35)
Other income (expense), net                 (364) 773 (133)
Nonoperating income (Expense), Total                 (2,448) (570) (2,514)
Income (loss) before income taxes                 11,115 11,609 8,207
Income tax (expense) benefit                 (3,980) (3,744) (3,050)
Net income (loss)                 7,135 7,865 5,157
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock                 (319) (1,662) (997)
Net income (loss) attributable to Parent 1,913 1,732 1,734 1,437 1,518 2,113 1,348 1,224 6,816 6,203 4,160
Comprehensive income attributable to Parent                 6,883 6,370 4,107
Comcast [Member]
                      
Management fee revenue                 897 848 800
Revenue                 897 848 800
Other operating and administrative                 403 401 420
Depreciation                 30 30 29
Amortization                 5 4 3
Costs and expenses, total                 438 435 452
Operating income (loss)                 459 413 348
Interest expense                 (1,523) (1,430) (1,439)
Investment income (loss), net                   8 3
Equity in net income (losses) of investees, net                 7,509 6,858 4,879
Other income (expense), net                 (2) 2 (19)
Nonoperating income (Expense), Total                 5,984 5,438 3,424
Income (loss) before income taxes                 6,443 5,851 3,772
Income tax (expense) benefit                 373 352 388
Net income (loss)                 6,816 6,203 4,160
Net income (loss) attributable to Parent                 6,816 6,203 4,160
Comprehensive income attributable to Parent                 6,883 6,370 4,107
Comcast Holdings [Member]
                      
Other operating and administrative                     5
Costs and expenses, total                     5
Operating income (loss)                     (5)
Interest expense                 (11) (23) (32)
Investment income (loss), net                 (13) 3 2
Equity in net income (losses) of investees, net                 7,540 6,536 5,734
Other income (expense), net                     1
Nonoperating income (Expense), Total                 7,516 6,516 5,705
Income (loss) before income taxes                 7,516 6,516 5,700
Income tax (expense) benefit                 9 7 12
Net income (loss)                 7,525 6,523 5,712
Net income (loss) attributable to Parent                 7,525 6,523 5,712
Comprehensive income attributable to Parent                 7,521 6,523 5,712
CCCL Parent [Member]
                      
Management fee revenue                 874 827 784
Revenue                 874 827 784
Other operating and administrative                 874 827 784
Costs and expenses, total                 874 827 784
Interest expense                 (212) (329) (338)
Equity in net income (losses) of investees, net                 7,430 6,665 5,598
Other income (expense), net                 2    
Nonoperating income (Expense), Total                 7,220 6,336 5,260
Income (loss) before income taxes                 7,220 6,336 5,260
Income tax (expense) benefit                 73 115 118
Net income (loss)                 7,293 6,451 5,378
Net income (loss) attributable to Parent                 7,293 6,451 5,378
Comprehensive income attributable to Parent                 7,276 6,460 5,387
Combined CCHMO Parents [Member]
                      
Management fee revenue                 548 516 488
Revenue                 548 516 488
Other operating and administrative                 548 516 488
Costs and expenses, total                 548 516 488
Interest expense                 (126) (135) (172)
Equity in net income (losses) of investees, net                 5,473 4,909 3,361
Nonoperating income (Expense), Total                 5,347 4,774 3,189
Income (loss) before income taxes                 5,347 4,774 3,189
Income tax (expense) benefit                 44 47 60
Net income (loss)                 5,391 4,821 3,249
Net income (loss) attributable to Parent                 5,391 4,821 3,249
Comprehensive income attributable to Parent                 5,392 4,821 3,249
NBCUniversal Media Parent [Member]
                      
Other operating and administrative                 855 899 678
Costs and expenses, total                 855 899 678
Operating income (loss)                 (855) (899) (678)
Interest expense                 (488) (430) (370)
Investment income (loss), net                 3 5  
Equity in net income (losses) of investees, net                 3,331 4,402 2,793
Other income (expense), net                 (1) (14) (59)
Nonoperating income (Expense), Total                 2,845 3,963 2,364
Income (loss) before income taxes                 1,990 3,064 1,686
Income tax (expense) benefit                 (22) (9) (3)
Net income (loss)                 1,968 3,055 1,683
Net income (loss) attributable to Parent                 1,968 3,055 1,683
Comprehensive income attributable to Parent                 2,017 3,068 1,605
Comcast Non-Guarantor Subsidiaries [Member]
                      
Service revenue                 64,657 62,570 55,842
Revenue                 64,657 62,570 55,842
Programming and production                 19,670 19,929 16,596
Other operating and administrative                 18,223 17,381 16,343
Advertising, marketing and promotion                 4,969 4,831 4,243
Depreciation                 6,224 6,120 6,011
Amortization                 1,612 1,644 1,593
Costs and expenses, total                 50,698 49,905 44,786
Operating income (loss)                 13,959 12,665 11,056
Interest expense                 (214) (174) (154)
Investment income (loss), net                 586 203 154
Equity in net income (losses) of investees, net                 1,882 4,014 1,648
Other income (expense), net                 (363) 785 (56)
Nonoperating income (Expense), Total                 1,891 4,828 1,592
Income (loss) before income taxes                 15,850 17,493 12,648
Income tax (expense) benefit                 (4,457) (4,256) (3,625)
Net income (loss)                 11,393 13,237 9,023
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock                 (319) (1,662) (997)
Net income (loss) attributable to Parent                 11,074 11,575 8,026
Comprehensive income attributable to Parent                 10,969 11,703 8,064
Elimination and Consolidation Adjustments [Member]
                      
Management fee revenue                 (2,319) (2,191) (2,072)
Revenue                 (2,319) (2,191) (2,072)
Other operating and administrative                 (2,319) (2,191) (2,072)
Costs and expenses, total                 (2,319) (2,191) (2,072)
Equity in net income (losses) of investees, net                 (33,251) (32,425) (24,048)
Nonoperating income (Expense), Total                 (33,251) (32,425) (24,048)
Income (loss) before income taxes                 (33,251) (32,425) (24,048)
Net income (loss)                 (33,251) (32,425) (24,048)
Net income (loss) attributable to Parent                 (33,251) (32,425) (24,048)
Comprehensive income attributable to Parent                 $ (33,175) $ (32,575) $ (24,017)