v3.10.0.1
Segment Information (Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Adjusted EBITDA $ 30,165 $ 27,956 $ 26,257
Adjustment for legal settlement (125) (250) 0
Adjustment for Sky transaction-related costs (355) 0 0
Depreciation (8,281) (7,914) (7,464)
Amortization (2,736) (2,216) (1,962)
Other operating gains 341 442 0
Interest expense (3,542) (3,086) (2,942)
Investment and other income (loss), net (225) 421 437
Income before income taxes 15,242 15,353 14,326
NBCUniversal Media LLC [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Adjusted EBITDA 8,633 8,181 7,163
Depreciation (1,001) (994) (861)
Amortization (1,107) (1,047) (944)
Other operating gains 141 337 0
Interest expense (489) (727) (595)
Investment and other income (loss), net (521) (144) 24
Income before income taxes $ 5,656 $ 5,606 $ 4,787