Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of allocated share-based compensation expense

The following table presents our aggregate stock-based compensation expense by type of costs and expenses per the Consolidated Statements of Income (in millions):



	Year Ended December 31,
	2014		2015		2016
Cost of revenues	$	535	$	806	$	1,157
Research and development	2,200		2,687		3,354
Sales and marketing	715		899		1,078
General and administrative	725		861		1,282
Discontinued operations	104		0		0
Total stock-based compensation expense	$	4,279	$	5,253	$	6,871

Schedule of restricted stock activity

The following table summarizes the activities for our unvested restricted stock units (RSUs) for the year ended December 31, 2016:



	Unvested Restricted Stock Units
	Number of Shares		Weighted- Average Grant-Date Fair Value
Unvested as of December 31, 2015	25,741,186		$	531.74
Granted	13,502,900		$	713.89
Vested	(12,002,071	)	$	532.87
Forfeited/canceled	(1,893,060	)	$	562.03
Unvested as of December 31, 2016	25,348,955		$	624.92