Stockholders' Equity - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Class A Common Stock
Aggregate Intrinsic Value
Common stock, closing share price (in usd per share)	$ 128.27
Employee Stock Options
Number of Shares
Beginning balance (in shares) | shares	8,443
Stock options exercised (in shares) | shares	(2,127)
Ending balance (in shares) | shares	6,316
Stock options vested and expected to vest as of period end (in shares) | shares	6,315
Stock options exercisable as of period end (in shares) | shares	4,827
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 7.10
Stock options exercised (in dollars per share)	5.21
Ending balance (in dollars per share)	7.74
Stock options vested and expected to vest as of period end (in dollars per share)	7.74
Stock options exercisable as of period end (in dollars per share)	$ 5.99
Weighted Average Remaining Contractual Term
Balance at period end	3 years 1 month 6 days
Stock options vested and expected to vest as of period end	3 years 1 month 6 days
Stock options exercisable as of period end	2 years 10 months 25 days
Aggregate Intrinsic Value
Balance at period end | $	$ 761	[1]
Stock options vested and expected to vest as of period end | $	761	[1]
Stock options exercisable as of period end | $	$ 590	[1]

[1] The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock option awards and the official closing price of our Class A common stock of $128.27, as reported on the NASDAQ Global Select Market on September 30, 2016.