CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Accounts receivable, allowances for doubtful accounts	$ 35	$ 38
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.000006	$ 0.000006
Class A Common Stock
Stockholders' equity:
Common stock, shares authorized	5,000,000,000	5,000,000,000
Common stock, shares issued	2,044,000,000	1,970,000,000
Common stock, shares outstanding	2,044,000,000	1,970,000,000
Common stock, outstanding shares subject to repurchase	4,000,000	6,000,000
Class B Common Stock
Stockholders' equity:
Common stock, shares authorized	4,141,000,000	4,141,000,000
Common stock, shares issued	564,000,000	577,000,000
Common stock, shares outstanding	564,000,000	577,000,000
Common stock, outstanding shares subject to repurchase	8,000,000	6,000,000