Segment Information (Intersegment Assets, Equity Affiliates Investments and Capital Expenditures Details) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total Assets	$ 551,669	$ 531,864
Investments in Equity Affiliates	3,695	6,245	$ 1,560
Capital Expenditures	19,635	21,251
Corporate and eliminations [Member]
Segment Reporting Information [Line Items]
Total Assets	(130,569)	(106,812)
Investments in Equity Affiliates	34	21
Capital Expenditures	263	310
Communications [Member]
Segment Reporting Information [Line Items]
Total Assets	521,252	485,357
Investments in Equity Affiliates	0	0
Capital Expenditures	17,410	19,509
WarnerMedia [Member]
Segment Reporting Information [Line Items]
Total Assets	137,264	132,453
Investments in Equity Affiliates	3,011	5,547
Capital Expenditures	1,013	581
Latin America [Member]
Segment Reporting Information [Line Items]
Total Assets	20,606	18,148
Investments in Equity Affiliates	650	677
Capital Expenditures	757	745
Xandr [Member]
Segment Reporting Information [Line Items]
Total Assets	3,116	2,718
Investments in Equity Affiliates	0	0
Capital Expenditures	$ 192	$ 106