14. STOCK-BASED COMPENSATION

The majority of the Company’s stock-based compensation arrangements vest over a five year vesting schedule and the Company’s stock options have a ten-year term. The Company recognizes stock-based compensation using the accelerated recognition method, treating each vesting tranche as if it were an individual grant.

The Company periodically grants stock options and restricted stock units (“RSUs”) for a fixed number of shares upon vesting to employees and non-employee Directors. The exercise price for stock options is greater than or equal to the fair market value of the shares at the grant date. RSUs deliver to the recipient a right to receive a specified number of shares of the Company’s common stock upon vesting. Unlike stock options, there is no cost to the employee at share issuance. The Company values its RSUs at the fair value of its common stock on the grant date, which is the closing price of its common stock on the grant date, less the present value of expected dividends during the vesting period, as the recipient is not entitled to dividends during the requisite service period. Upon vesting of the RSUs, the Company withholds shares of common stock in an amount sufficient to cover the minimum statutory tax withholding obligations and issues shares of its common stock for the remaining amount.

Employees may elect to receive 50% of their target incentive compensation under the Company’s Corporate Incentive Compensation Plan (the “CICP”) in the form of RSUs instead of cash. If elected by an employee, the equity amount is equal in value on the date of grant to 50% of his or her target incentive opportunity, based on the employee’s base salary. The number of RSUs granted is determined by dividing 50% of the employee’s target incentive opportunity by 85% of the closing price of its common stock on the grant date, less the present value of expected dividends during the vesting period. If elected, the award vests 100% on the CICP payout date of the following year for all participants. Vesting is conditioned upon the performance conditions of the CICP and on continued employment; if threshold funding does not occur, the equity grant will be cancelled. The Company considers vesting to be probable on the grant date and recognizes the associated stock-based compensation expense over the requisite service period beginning on the grant date and ending on the vesting date.

The Company grants options that allow for the settlement of vested stock options on a net share basis (“net settled stock options”). With net settled stock options, the employee does not surrender any cash or shares upon exercise. Rather, the Company withholds the number of shares to cover the option exercise price and the minimum statutory tax withholding obligations from the shares that would otherwise be issued upon exercise. The exercise of stock options on a net share basis results in fewer shares issued by the Company.

Share-Based Compensation Plans:

(a) 2004 Long-Term Incentive Plan (as amended and restated)

In 2004, the Company adopted the 2004 Long-Term Incentive Plan (as amended and restated, the “2004 Plan”) to provide employees, non-employee Directors, and consultants with opportunities to purchase stock through incentive stock options and non-qualified stock options. In addition to options, eligible participants under the 2004 Plan may be granted stock purchase rights and other stock-based awards. In June 2016, the Company’s stockholders approved an amendment to the 2004 Plan, which increased the number of shares authorized for issuance under the plan to 30,000,000, extended the term of the plan to 2026, and limited annual compensation to any non-employee Director to $500,000. The 2004 Plan was previously amended and approved by the Company’s stockholders in July 2011, which increased the number of shares authorized for issuance under the plan to 24,000,000, giving effect to the two-for-one stock split approved by the Company’s Board of Directors in 2014 (the “Stock Split”), and extending the term of the plan to 2021. Since 2006, the Company has granted to each non-employee director of the Company unrestricted shares of common stock on an annual basis in consideration of their board service, prorated if the non-employee director joins the Company’s Board of Directors after the annual equity grant is made. The number of unrestricted shares granted to non-employee Directors was equal to $20,000, $119,000, and $95,000, divided by the fair market value of the Company’s common stock on the grant dates, for 2016, 2015, and 2014, respectively. On May 18, 2016, the Company changed the annual equity grant from unrestricted common stock to RSUs, vesting 25% on the date of the annual meeting of stockholders and 25% quarterly thereafter. During 2016, the Company granted 36,000 RSUs to non-employee Directors equal to $961,000.

As of December 31, 2016, approximately 10,597,000 shares were subject to outstanding options and stock-based awards under the 2004 Plan.

(b) 2006 Employee Stock Purchase Plan

In 2006, the Company adopted the 2006 Employee Stock Purchase Plan (the “2006 ESPP”) pursuant to which the Company’s employees are entitled to purchase up to an aggregate of 1,000,000 shares, giving effect to the Stock Split, of common stock at a price equal to at least 85% of the fair market value of the Company’s common stock on either the commencement date or completion date for offerings under the plan, whichever is less, or such higher price as the Company’s Board of Directors may establish from time to time. Until the Company’s Board of Directors determines otherwise, the Board has set the purchase price at 95% of the fair market value on the completion date of the offering period. As a result, the 2006 ESPP is non-compensatory and is tax qualified. Therefore, as of December 31, 2016, no compensation expense related to shares issued under the plan had been recognized. In October 2012, the Company’s Board of Directors amended the term of the 2006 ESPP such that it will continue until there are no shares remaining to be issued under the plan or until the plan is terminated by the Board of Directors, whichever occurs first. As of December 31, 2016, approximately 351,000 shares had been issued thereunder.

Shares reserved

As of December 31, 2016, there were approximately 10,230,000 shares remaining for issuance for future equity grants under the Company’s stock plans, consisting of approximately 9,581,000 shares under the 2004 Plan and approximately 649,000 shares under the 2006 ESPP.

Equity grants, assumptions and activity

During 2016, the Company issued approximately 1,154,000 shares to its employees under the Company’s share-based compensation plans and approximately 27,000 shares to the non-employee members of its Board of Directors.

The following table presents the stock-based compensation expense included in the Company’s consolidated statements of operations:


	Year ended December 31,
(in thousands)	2016			2015			2014
Stock-based compensation expense:
Cost of revenues	$	11,459		$	8,772		$	5,335
Operating expenses		29,362			21,282			13,870

Total stock-based compensation before tax		40,821			30,054			19,205
Income tax benefit		(12,198	)		(8,098	)		(5,563	)

Stock Options

The Company estimates the fair value of stock options using a Black-Scholes option valuation model. Key inputs used to estimate the fair value of stock options include the exercise price of the award, the expected term of the option, the expected volatility of the Company’s common stock over the option’s expected term, the risk-free interest rate over the option’s expected term, and the Company’s expected annual dividend yield. The amount of stock-based compensation recognized during a period is based on the value of the awards that are ultimately expected to vest. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Ultimately, the Company recognizes the actual expense over the vesting period only for the shares that vest. The weighted-average grant-date fair value for stock options granted in 2016, 2015, and 2014, was $8.31, $7.62 and $7.58 per share, respectively.

The weighted-average assumptions used in the Black-Scholes option valuation model are as follows:


	Year ended December 31,
	2016			2015			2014
Expected annual volatility ⁽¹⁾		40	%		45	%		47	%
Expected term in years ⁽²⁾		4.4			4.5			4.4
Risk-free interest rate ⁽³⁾		1.21	%		1.34	%		1.33	%
Expected annual dividend yield ⁽⁴⁾		0.63	%		0.68	%		0.44	%

⁽¹⁾	The expected annual volatility for each grant is determined based on the average of historical daily price changes of the Company’s common stock over a period of time which approximates the expected option term.

⁽²⁾	The expected option term for each grant is determined based on the historical exercise behavior of employees and post-vesting employment termination behavior.

⁽³⁾	The risk-free interest rate is based on the yield of U.S. Treasury securities with a maturity that is commensurate with the expected option term at the time of grant.

⁽⁴⁾

The expected annual dividend yield is based on the weighted-average of the dividend yield assumptions used for options granted during the applicable period. The expected annual dividend has historically been based on the expected dividend of $0.06 per share, per year ($0.015 per share, per quarter times 4 quarters), on a post-split basis, divided by the average stock price. On May 27, 2014, the Company announced an increase in its quarterly cash dividend from $0.015 to $0.03 per share. Thus, for grants made after this date, the expected annual dividend is based on the expected dividend of $0.12 per share, per year ($0.03 per share, per quarter times 4 quarters), divided by the average stock price.

The Company elected to adopt the alternative transition method (“short cut method”) in calculating its historical pool of windfall tax benefits in regards to its share-based compensation.

The following table summarizes the combined stock option activity under the Company’s stock option plans for the year ended December 31, 2016:


	Shares (in thousands)			Weighted-average exercise price		Weighted-average remaining contractual term (in years)		Aggregate intrinsic value (in thousands)
Options outstanding as of January 1, 2016		6,563		$	16.01
Granted		2,691			25.72
Exercised		(1,275	)		14.41
Forfeited/Cancelled		(516	)		20.85

Options outstanding as of December 31, 2016		7,463		$	19.45

Vested and expected to vest as December 31, 2016		6,154		$	18.99		7.3	$	104,655

Exercisable as of December 31, 2016		2,696		$	14.21		5.7	$	58,741

The aggregate intrinsic value of stock options exercised (i.e., the difference between the market price at exercise and the price paid by the employee at exercise) in 2016, 2015, and 2014 was $19.9 million, $18.6 million and $13.2 million, respectively. The aggregate intrinsic value of stock options outstanding and exercisable as of December 31, 2016 is based on the difference between the closing price of the Company’s stock of $36.00 on December 31, 2016 and the exercise price of the applicable stock options.

As of December 31, 2016, the Company had unrecognized stock-based compensation expense related to the unvested portion of stock options of approximately $14.5 million that is expected to be recognized as expense over a weighted-average period of approximately 2.2 years.

RSUs

The weighted-average grant-date fair value for RSUs granted in 2016, 2015, and 2014 was $25.54, $20.49, and $19.88, respectively. The following table summarizes the combined RSU activity for periodic grants and the CICP under the 2004 Plan for the year ended December 31, 2016:


	Shares (in thousands)			Weighted- Average Grant-Date Fair Value		Aggregate Intrinsic Value (in thousands)
Nonvested as of January 1, 2016		2,607		$	20.03
Granted		1,929			25.54
Vested		(1,071	)		19.41
Forfeited		(304	)		22.22

Nonvested as of December 31, 2016		3,161		$	23.39	$	113,824

Expected to vest as of December 31, 2016		2,350		$	23.55	$	84,592

The RSUs associated with periodic grants generally vest over five years with 20% vesting after one year and the remaining 80% vesting in equal quarterly installments over the remaining four years. Approximately 225,000 RSUs granted in connection with the 2016 CICP are expected to vest 100% in March 2017.

The fair value of RSUs vested in 2016, 2015, and 2014 was $29.2 million, $14.9 million, and $8.0 million, respectively. The aggregate intrinsic value of RSUs outstanding and expected to vest as of December 31, 2016 is based on the closing price of the Company’s stock of $36.00 on December 31, 2016.

As of December 31, 2016, the Company had approximately $27.8 million of unrecognized stock-based compensation expense related to all unvested RSUs that is expected to be recognized as expense over a weighted-average period of approximately 2.1 years.