Acquisitions, Dispositions And Other Adjustments (Fair Value of Assets Acquired and Liabilities Assumed) (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Assets acquired
Noncurrent Inventories and Theatrical Film and Television Production Costs	$ 7,221	$ 0
Goodwill	146,475	105,449
Liabilities assumed
Debt maturing within one year	14,905	$ 38,374
Time Warner Inc. [Member]
Assets acquired
Cash	1,655
Accounts Receivable	9,016
All other current assets	3,150
Noncurrent Inventories and Theatrical Film and Television Production Costs	5,719
Property, plant and equipment	4,906
Investments and other assets	9,428
Goodwill	38,955
Total assets acquired	129,609
Liabilities assumed
Current liabilities, excluding current portion of long-term debt	8,280
Debt maturing within one year	4,471
Long-term debt	18,394
Other noncurrent liabilities	19,105
Total liabilities assumed	50,250
Net assets acquired	79,359
Noncontrolling interest	(1)
Aggregate value of consideration paid	79,358
Time Warner Inc. [Member] | Distribution Networks [Member]
Assets acquired
Intangible assets subject to amortization	17,470
Time Warner Inc. [Member] | Released television and film content [Member]
Assets acquired
Intangible assets subject to amortization	10,929
Time Warner Inc. [Member] | Trademarks/trade names [Member]
Assets acquired
Intangible assets subject to amortization	18,081
Time Warner Inc. [Member] | Other [Member]
Assets acquired
Intangible assets subject to amortization	$ 10,300