Condensed Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Property and equipment - accumulated depreciation	$ 55,217	$ 54,388
Other intangible assets - accumulated amortization	$ 21,976	$ 19,825
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Treasury stock (in shares)	872,791,028	872,791,028
Class A Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	7,500,000,000	7,500,000,000
Common stock, shares issued (in shares)	5,453,083,882	5,444,002,825
Common stock, shares outstanding (in shares)	4,580,292,854	4,571,211,797
Class B Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	9,444,375	9,444,375
Common stock, shares outstanding (in shares)	9,444,375	9,444,375