v3.10.0.1
Related Party Transactions (Condensed Consolidated Balance Sheet) (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Related Party Transaction [Line Items]    
Receivables, net $ 11,104 $ 8,834
Accounts payable and accrued expenses related to trade creditors 8,494 6,908
Accrued expenses and other current liabilities 10,721 6,620
Long-term debt, less current portion 107,345 59,422
Other noncurrent liabilities 15,329 10,972
NBCUniversal Media LLC [Member]    
Related Party Transaction [Line Items]    
Receivables, net 7,293 6,967
Note receivable from Comcast 2,054 0
Accounts payable and accrued expenses related to trade creditors 1,933 1,663
Accrued expenses and other current liabilities 2,195 2,394
Note payable to Comcast 54 1,831
Long-term debt, less current portion 12,731 12,275
Other noncurrent liabilities 5,177 4,153
Comcast And Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]    
Related Party Transaction [Line Items]    
Receivables, net 464 326
Note receivable from Comcast 2,054 0
Accounts payable and accrued expenses related to trade creditors 78 54
Accrued expenses and other current liabilities 32 50
Note payable to Comcast 54 1,831
Long-term debt, less current portion 701 610
Other noncurrent liabilities $ 410 $ 389