v3.7.0.1
Supplemental Financial Information (Net Cash Provided by Operating Activities)(Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Supplemental Financial Information [Line Items]    
Net income $ 2,647 $ 2,224
Adjustments to reconcile net income to net cash provided by operating activities:    
Depreciation and amortization 2,502 2,278
Share-based compensation 173 153
Noncash interest expense (income), net 58 55
Equity in net (income) losses of investees, net (36) 11
Cash received from investees 17 16
Net (gain) loss on investment activity and other (53) (126)
Deferred income taxes 265 217
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:    
Current and noncurrent receivables, net 465 562
Film and television costs, net 46 (80)
Accounts payable and accrued expenses related to trade creditors (190) 12
Other operating assets and liabilities (238) 77
Net cash provided by operating activities 5,656 5,399
NBCUniversal Media LLC [Member]    
Supplemental Financial Information [Line Items]    
Net income 1,273 1,082
Adjustments to reconcile net income to net cash provided by operating activities:    
Depreciation and amortization 508 414
Equity in net (income) losses of investees, net 26 2
Cash received from investees 14 12
Net (gain) loss on investment activity and other (18) (114)
Deferred income taxes 9 48
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:    
Current and noncurrent receivables, net 104 349
Film and television costs, net 46 (84)
Accounts payable and accrued expenses related to trade creditors (190) (139)
Other operating assets and liabilities (295) (393)
Net cash provided by operating activities $ 1,477 $ 1,177