Share Based Awards (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Stock Option Activity

		Options Outstanding
					Weighted-	Aggregate
	Number of				Average	Intrinsic
	Shares		Weighted-		Remaining	Value
	Available for	Number of	Average		Contractual	(In thousands)
	Issuance	Shares	Exercise Price		Term (Years)	Aggregate
Balance—December 31, 2012	574,597	10,950,917	$	2.11	8.78	$	17,329
Authorized	4,478,151	—
Granted	(4,891,242)	4,891,242		4.33
Exercised (1)	—	(695,482)		1.72
Canceled	1,815,795	(1,815,795)		2.55
Repurchased	108,037	—
Balance—December 31, 2013	2,085,338	13,330,882	$	2.90	8.38	$	38,339
Authorized	9,913,915	—
Stock options granted	(5,373,131)	5,373,131		6.97
Restricted stock units granted	(480,456)	—
Exercised (1)	—	(1,089,708)		2.27
Stock options canceled	1,178,737	(1,178,737)		4.55
Restricted stock units canceled	1,667	—
Repurchased	66,088	—
Balance—December 31, 2014	7,392,158	16,435,568	$	4.15	7.83	$	95,791
Authorized	5,418,242	—
Stock options granted	(1,089,100)	1,089,100		6.95
Restricted stock units granted	(9,932,561)	—
Exercised (1)	9,019	(2,817,915)		2.12
Stock options canceled	3,208,006	(3,208,006)		5.61
Restricted stock units canceled	1,653,927	—
Repurchased	12,545	—
Balance—December 31, 2015	6,672,236	11,498,747		4.51	6.86		6,256
Vested and exercisable—December 31, 2015		7,167,464		3.55		$	6,202
Vested and expected to vest (2)—December 31, 2015		11,032,059		4.43		$	6,250

(1) Includes early exercises of 42,772 and126,386in 2014 and 2013, respectively. In 2015 no shares of common stock were issued for the exercise of common stock options prior to their vesting dates, or early exercises.

(2) Options expected to vest are net of an estimated forfeiture rate.

Additional Information Regarding Options

	Options Outstanding				Options Exercisable
		Weighted-
		Average
		Remaining	Weighted-			Weighted-
	Number of	Contractual	Average		Number of	Average
Range of exercises	Shares	Term (Years)	Exercise Price		Shares	Exercise Price
$0.04 — $1.75	2,360,113	5.04	$	1.07	2,356,759	$	1.07
$2.90 — $3.70	2,683,361	6.09		3.58	2,146,702		3.58
$3.77 — $5.77	3,938,687	7.32		5.02	1,920,743		4.83
$6.20 — $9.87	2,374,992	8.56		7.73	695,741		7.76
$10.80 — $12.05	141,594	8.53		11.31	47,519		11.33
Outstanding at December 31, 2015	11,498,747	6.86	$	4.51	7,167,464	$	3.55

Schedule of Stock-based Compensation Expense Recognized (in thousands)

	Year ended December 31,
	2015		2014		2013
Contra-revenue	$	—	$	123	$	78
Cost of revenue		2,774		1,353		327
Research and development		10,607		5,980		5,238
Sales and marketing		9,508		5,930		1,893
General and administrative		5,902		3,363		931
Total	$	28,791	$	16,749	$	8,467

Schedule of Assumptions Used for Calculating the Fair Value of Employee Option Grants

	Year ended December 31,
	2015	2014	2013
Expected dividend yield	—	—	—
Risk-free interest rate	1.6% - 1.8%	1.7% - 2.1%	1.1% - 1.9%
Expected volatility	43% - 45%	48% - 56%	52% - 53%
Expected life (in years)	5.5 - 6.1	5.6 - 6.5	5.9 - 6.3

Schedule of Assumptions Used for Calculating the Fair Value of Employee stock purchase plans

	Year ended December 31,
	2015	2014
Expected dividend yield	—	—
Risk-free interest rate	0.1% - 0.7%	0.1% - 0.5%
Expected volatility	34% - 35%	47% - 49%
Expected life (in years)	0.5 - 2	0.7 - 2.2

Schedule of Unrecognized Stock-based Compensation

	Unrecognized		Remaining
	Stock-based		Weighted-Average
	Compensation		Recognition
	Expense		Period
	(in millions)		(in years)
Stock options	$	9.6	1.8
Restricted stock		40.1	3.2
ESPP		2.5	0.7
Total	$	52.2

Restricted Stock

Schedule of Restricted Stock and RSU Activity

	Restricted Stock
		Time - and -
	Time - based	performance based	Total
	shares	shares	shares
Unvested, December 31, 2012	1,460,413	1,278,912	2,739,325
Granted	—	—	—
Vested	(573,695)	(247,010)	(820,705)
Unvested, December 31, 2013	886,718	1,031,902	1,918,620
Granted	16,294	—	16,294
Vested	(491,313)	(586,204)	(1,077,517)
Cancelled/Forfeited	(350,440)	(413,152)	(763,592)
Unvested, December 31, 2014	61,259	32,546	93,805
Granted	—	—	—
Vested	(41,137)	(32,546)	(73,683)
Cancelled/Forfeited	(20,122)	—	(20,122)
Unvested, December 31, 2015	—	—	—

RSUs

Schedule of Restricted Stock and RSU Activity

	Restricted Stock Units
		Weighted-
		Average
	Number of	Grant Date
	Shares	Fair Value
Unvested, December 31, 2013	—	$	—
Granted	480,456		9.45
Vested	—		—
Cancelled/Forfeited	(1,667)		9.18
Unvested, December 31, 2014	478,789	$	9.45
Granted	9,932,561		6.92
Vested	(924,461)		—
Cancelled/Forfeited	(1,653,927)		8.06
Unvested, December 31, 2015	7,832,962	$	6.66