Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowances	$ 61	$ 67
Common stock, par value (in USD per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	857,072,063	851,675,119
Common stock, shares outstanding (in shares)	855,557,671	850,180,317
Treasury stock, at cost (in shares)	1,514,392	1,494,802