Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

The following table summarizes the activities of stock option awards under the Stock Plans for the year ended December 31, 2015:



	Shares Subject to Options Outstanding
	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value⁽¹⁾
	(in thousands)				(in years)	(in millions)
Balance as of December 31, 2014	12,984		$	4.78
Stock options exercised	(4,541	)	0.48
Balance as of December 31, 2015	8,443		$	7.10	3.7	$	824
Stock options vested and expected to vest as of December 31, 2015	8,441		$	7.10	3.7	$	824
Stock options exercisable as of December 31, 2015	6,250		$	5.19	3.3	$	622


(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, as reported on the NASDAQ Global Select Market, of $104.66 on December 31, 2015.

The following table summarizes additional information regarding outstanding and exercisable options under the Stock Plans at December 31, 2015:



	Options Outstanding				Options Exercisable
Exercise Price (Range)	Number of Shares	Weighted Average Remaining Contractual Term	Weighted Average Exercise Price		Number of Shares	Weighted Average Exercise Price
	(in thousands)	(in years)			(in thousands)
$0.10 - 0.18	446	0.6	$	0.11	446	$	0.11
0.29 - 0.33	1,182	1.5	0.32		1,182	0.32
1.85	968	3.0	1.85		968	1.85
2.95	1,147	3.6	2.95		1,147	2.95
10.39	3,500	4.6	10.39		2,334	10.39
15.00	1,200	4.8	15.00		173	15.00
	8,443	3.7	$	7.10	6,250	$	5.19

The following table summarizes the activities for our unvested RSUs for the year ended December 31, 2015:



	Unvested RSUs⁽¹⁾
	Number of Shares		Weighted Average Grant Date Fair Value
	(in thousands)
Unvested at December 31, 2014	138,055		$	55.89
Granted	31,507		82.15
Vested	(46,434	)	49.19
Forfeited	(6,719	)	51.19
Unvested at December 31, 2015	116,409		$	65.95


(1)	Unvested shares include inducement awards issued in connection with an acquisition in 2014 and are subject to the terms, restrictions, and conditions of separate non-plan RSU award agreements.