CONSOLIDATED BALANCE SHEET (PARENTHETICALS) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS:
Accounts receivable, allowance for doubtful accounts	$ 151	$ 129
INVESTMENT IN CABLE PROPERTIES:
Property, plant and equipment, accumulated depreciation	$ 27,656	$ 23,075
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	250,000,000	250,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	900,000,000	900,000,000
Common stock, shares issued (in shares)	209,975,963	225,353,807
Common stock, shares outstanding (in shares)	209,975,963	225,353,807
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	1,000	1,000
Common stock, shares issued (in shares)	1	1
Common stock, shares outstanding (in shares)	1	1