Common Stock and Stockholders' Equity

3 Months Ended

Mar. 31, 2016

Equity [Abstract]

Common Stock and Stockholders' Equity

Note 8. Common Stock and Stockholders’ Equity

Common Stock

As of March 31, 2016 and December 31, 2015, there were 400 million shares authorized for issuance with a par value of $0.01 per share.  There were 92.0 million and 90.9 million shares of common stock issued and 91.5 million and 90.3 million shares outstanding as of March 31, 2016 and December 31, 2015, respectively. Included within the number of shares issued and outstanding were 0.2 million and 0.3 million shares of common stock subject to repurchase, as of March 31, 2016 and December 31, 2015, respectively.

Preferred Stock

As of March 31, 2016 and December 31, 2015, 10.0 million shares of preferred stock were authorized for issuance with a par value of $0.01 per share and no shares of preferred stock were issued or outstanding.

Employee Equity Plans

Employee Stock Purchase Plan

Under our Employee Stock Purchase Plan, or ESPP, eligible employees are granted options to purchase shares of our common stock through payroll deductions. The ESPP provides for eighteen-month offering periods, which include three six-month purchase periods. At the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of our common stock at the beginning of an offering period or the fair market value of our common stock at the end of the purchase period.  No shares of common stock were purchased under the ESPP during the three months ended March 31, 2016. Pursuant to the terms of the ESPP, the number of shares reserved under the ESPP increased by 0.9 million shares on January 1, 2016.  As of March 31, 2016, 3.8 million shares of common stock were available for issuance under the ESPP.

Stock Option and Grant Plans

Our board of directors adopted the 2009 Stock Option and Grant Plan, or the 2009 Plan, in July 2009. The 2009 Plan was terminated in connection with our IPO in May 2014, and accordingly, no shares are available for issuance under this plan. The 2009 Plan continues to govern outstanding awards granted thereunder.

Our 2014 Stock Option and Incentive Plan, or the 2014 Plan, serves as the successor to our 2009 Plan. Pursuant to the terms of the 2014 Plan, the number of shares reserved for issuance under the 2014 Plan increased by 4.5 million shares on January 1, 2016. As of March 31, 2016, we had 7.5 million shares of common stock available for future grants under the 2014 Plan.

The following table summarizes our stock option and RSU award activities for the three months ended March 31, 2016 (in thousands, except per share information):

				Options Outstanding									RSUs Outstanding
									Weighted
									Average							Weighted
	Shares						Weighted		Remaining		Aggregate					Average
	Available			Number of			Average		Contractual		Intrinsic		Outstanding			Grant Date
	for Grant			Shares			ExercisePrice		Term		Value		RSUs			Fair Value
									(In years)
Outstanding — January 1, 2016		4,323			10,778		$	11.94		7.96	$	156,262		6,417		$	19.54
Increase in authorized shares		4,516
Stock options granted		(110	)		110			18.48
RSUs granted		(1,426	)											1,426			14.77
Stock options exercised					(386	)		4.96
RSUs vested														(785	)		16.70
Stock options forfeited or    canceled		72			(72	)		24.32
RSUs forfeited or cancelled		91												(91	)		20.67
Outstanding — March 31, 2016		7,466			10,430		$	12.18		7.78	$	91,213		6,967		$	18.87

Aggregate intrinsic value for options outstanding represents the difference between the closing stock price of our common stock and the exercise price of outstanding, in-the-money options. Our closing stock price as reported on the New York Stock Exchange as of March 31, 2016 was $20.93.

As of March 31, 2016, we had a total of $167.8 million in future share-based compensation expense related to all equity awards, net of estimated forfeitures, to be recognized over a weighted average period of 2.9 years.

Early Exercise of Stock Options and Purchase of Unvested Stock Awards

Certain of our stock options permit early exercise. Common stock purchased pursuant to an early exercise of stock options or unvested stock awards is not deemed to be outstanding for financial reporting purposes until those shares vest. Therefore, cash received in exchange for unvested shares is recorded as a liability and is transferred into common stock and additional paid-in capital as the shares vest. Upon termination of service, we may, at our discretion, repurchase unvested shares acquired through early exercise of stock options or purchase of unvested stock awards at a price equal to the price per share paid upon the exercise of such options or the purchase of such unvested stock awards. As of March 31, 2016 and December 31, 2015, there were 0.2 million and 0.3 million shares, respectively, outstanding as a result of the early exercise of stock options and purchase of unvested stock awards by our employees and directors that were classified as accrued liabilities for an aggregated amount of $0.8 million and $1.0 million, respectively.