Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable allowance	$ 583	$ 455
Preferred Stock, Par Value	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par value	$ 0.001	$ 0.001
Common Stock, Shares authorized	5,600,000,000	5,600,000,000
Common Stock, Shares issued	1,282,000,000	1,308,000,000
Common Stock, Shares outstanding	1,282,000,000	1,308,000,000