v3.3.1.900
Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Operating Activities      
Net cash provided by (used in) operating activities $ 18,778 $ 16,945 $ 14,160
Investing Activities      
Capital expenditures (8,499) (7,420) (6,596)
Cash paid for intangible assets (1,370) (1,122) (1,009)
Acquisitions and construction of real estate properties (178) (43) (1,904)
Acquisitions, net of cash acquired (1,786) (477) (99)
Proceeds from sales of businesses and investments 433 666 1,083
Purchases of investments (784) (191) (1,223)
Other 220 (146) 234
Net cash provided by (used in) investing activities (11,964) (8,733) (9,514)
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 135 (504) 1,345
Proceeds from borrowings 5,486 4,182 2,933
Repurchases and repayments of debt (4,378) (3,175) (2,444)
Repurchases and retirements of common stock (6,750) (4,251) (2,000)
Dividends paid (2,437) (2,254) (1,964)
Issuances of common stock 36 35 40
Purchase of NBCUniversal noncontrolling common equity interest     (10,761)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock (232) (220) (215)
Settlement of Station Venture liability     (602)
Other (289) 167 (211)
Net cash provided by (used in) financing activities (8,429) (6,020) (13,879)
Increase (decrease) in cash and cash equivalents (1,615) 2,192 (9,233)
Cash and cash equivalents, beginning of period 3,910 1,718 10,951
Cash and cash equivalents, end of period 2,295 3,910 1,718
Elimination and Consolidation Adjustments [Member]      
Operating Activities      
Net cash provided by (used in) operating activities 0 0 0
Investing Activities      
Net transactions with affiliates 0 0 0
Capital expenditures 0 0 0
Cash paid for intangible assets 0 0 0
Acquisitions and construction of real estate properties 0 0 0
Acquisitions, net of cash acquired 0 0 0
Proceeds from sales of businesses and investments 0 0 0
Purchases of investments 0 0 0
Other 0 0 0
Net cash provided by (used in) investing activities 0 0 0
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 0 0 0
Proceeds from borrowings 0 0 0
Repurchases and repayments of debt 0 0 0
Repurchases and retirements of common stock 0 0 0
Dividends paid 0 0 0
Issuances of common stock 0 0 0
Purchase of NBCUniversal noncontrolling common equity interest     0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock 0 0 0
Settlement of Station Venture liability     0
Other 0 0 0
Net cash provided by (used in) financing activities 0 0 0
Increase (decrease) in cash and cash equivalents 0 0 0
Cash and cash equivalents, beginning of period 0 0 0
Cash and cash equivalents, end of period 0 0 0
Comcast Parent [Member]      
Operating Activities      
Net cash provided by (used in) operating activities (792) (354) (600)
Investing Activities      
Net transactions with affiliates 6,559 4,784 66
Capital expenditures (27) (3) (7)
Cash paid for intangible assets (6) (6) (4)
Acquisitions and construction of real estate properties 0 0 0
Acquisitions, net of cash acquired 0 0 0
Proceeds from sales of businesses and investments 0 0 0
Purchases of investments (7) (19) (11)
Other 7 0 0
Net cash provided by (used in) investing activities 6,526 4,756 44
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 400 (1,350) 1,349
Proceeds from borrowings 5,486 4,180 2,933
Repurchases and repayments of debt (2,650) (1,000) 0
Repurchases and retirements of common stock (6,750) (4,251) (2,000)
Dividends paid (2,437) (2,254) (1,964)
Issuances of common stock 36 35 40
Purchase of NBCUniversal noncontrolling common equity interest     0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock 0 0 0
Settlement of Station Venture liability     0
Other 181 238 198
Net cash provided by (used in) financing activities (5,734) (4,402) 556
Increase (decrease) in cash and cash equivalents 0 0 0
Cash and cash equivalents, beginning of period 0 0 0
Cash and cash equivalents, end of period 0 0 0
Comcast Holdings [Member]      
Operating Activities      
Net cash provided by (used in) operating activities 48 9 (3)
Investing Activities      
Net transactions with affiliates (48) (9) 3
Capital expenditures 0 0 0
Cash paid for intangible assets 0 0 0
Acquisitions and construction of real estate properties 0 0 0
Acquisitions, net of cash acquired 0 0 0
Proceeds from sales of businesses and investments 0 0 0
Purchases of investments 0 0 0
Other 0 0 0
Net cash provided by (used in) investing activities (48) (9) 3
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 0 0 0
Proceeds from borrowings 0 0 0
Repurchases and repayments of debt 0 0 0
Repurchases and retirements of common stock 0 0 0
Dividends paid 0 0 0
Issuances of common stock 0 0 0
Purchase of NBCUniversal noncontrolling common equity interest     0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock 0 0 0
Settlement of Station Venture liability     0
Other 0 0 0
Net cash provided by (used in) financing activities 0 0 0
Increase (decrease) in cash and cash equivalents 0 0 0
Cash and cash equivalents, beginning of period 0 0 0
Cash and cash equivalents, end of period 0 0 0
CCCL Parent [Member]      
Operating Activities      
Net cash provided by (used in) operating activities (167) (139) (245)
Investing Activities      
Net transactions with affiliates 840 139 2,580
Capital expenditures 0 0 0
Cash paid for intangible assets 0 0 0
Acquisitions and construction of real estate properties 0 0 0
Acquisitions, net of cash acquired 0 0 0
Proceeds from sales of businesses and investments 0 0 0
Purchases of investments 0 0 0
Other 0 0 0
Net cash provided by (used in) investing activities 840 139 2,580
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 0 0 0
Proceeds from borrowings 0 0 0
Repurchases and repayments of debt (673) 0 (2,335)
Repurchases and retirements of common stock 0 0 0
Dividends paid 0 0 0
Issuances of common stock 0 0 0
Purchase of NBCUniversal noncontrolling common equity interest     0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock 0 0 0
Settlement of Station Venture liability     0
Other 0 0 0
Net cash provided by (used in) financing activities (673) 0 (2,335)
Increase (decrease) in cash and cash equivalents 0 0 0
Cash and cash equivalents, beginning of period 0 0 0
Cash and cash equivalents, end of period 0 0 0
NBCUniversal Media Parent [Member]      
Operating Activities      
Net cash provided by (used in) operating activities (1,398) (1,299) (1,102)
Investing Activities      
Net transactions with affiliates 2,839 2,247 (470)
Capital expenditures 0 0 0
Cash paid for intangible assets 0 0 0
Acquisitions and construction of real estate properties 0 0 0
Acquisitions, net of cash acquired 0 0 0
Proceeds from sales of businesses and investments 4 8 2
Purchases of investments (407) (10) (3)
Other (5) 5 108
Net cash provided by (used in) investing activities 2,431 2,250 (363)
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net 0 0 0
Proceeds from borrowings 0 0 0
Repurchases and repayments of debt (1,004) (902) (88)
Repurchases and retirements of common stock 0 0 0
Dividends paid 0 0 0
Issuances of common stock 0 0 0
Purchase of NBCUniversal noncontrolling common equity interest     (3,200)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock 0 0 0
Settlement of Station Venture liability     0
Other 0 0 (40)
Net cash provided by (used in) financing activities (1,004) (902) (3,328)
Increase (decrease) in cash and cash equivalents 29 49 (4,793)
Cash and cash equivalents, beginning of period 385 336 5,129
Cash and cash equivalents, end of period 414 385 336
Comcast Non-Guarantor Subsidiaries [Member]      
Operating Activities      
Net cash provided by (used in) operating activities 21,087 18,728 16,110
Investing Activities      
Net transactions with affiliates (10,190) (7,161) (2,179)
Capital expenditures (8,472) (7,417) (6,589)
Cash paid for intangible assets (1,364) (1,116) (1,005)
Acquisitions and construction of real estate properties (178) (43) (1,904)
Acquisitions, net of cash acquired (1,786) (477) (99)
Proceeds from sales of businesses and investments 429 658 1,081
Purchases of investments (370) (162) (1,209)
Other 218 (151) 126
Net cash provided by (used in) investing activities (21,713) (15,869) (11,778)
Financing Activities      
Proceeds from (repayments of) short-term borrowings, net (265) 846 (4)
Proceeds from borrowings 0 2 0
Repurchases and repayments of debt (51) (1,273) (21)
Repurchases and retirements of common stock 0 0 0
Dividends paid 0 0 0
Issuances of common stock 0 0 0
Purchase of NBCUniversal noncontrolling common equity interest     (7,561)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock (232) (220) (215)
Settlement of Station Venture liability     (602)
Other (470) (71) (369)
Net cash provided by (used in) financing activities (1,018) (716) (8,772)
Increase (decrease) in cash and cash equivalents (1,644) 2,143 (4,440)
Cash and cash equivalents, beginning of period 3,525 1,382 5,822
Cash and cash equivalents, end of period $ 1,881 $ 3,525 $ 1,382