Note 7 - Stock-based Compensation |
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Disclosure of Compensation Related Costs, Share-based Payments [Text Block] | 7. STOCK-BASED COMPENSATION2014 Equity Incentive Plan (the “2014 Plan”) The Board of Directors adopted the 2014 Plan in April 2013, and the stockholders approved it in June 2013. In October 2014, the Board of Directors approved certain amendments to the 2014 Plan. The 2014 Plan, as amended, became effective on November 13, 2014 and provides for the issuance of up to 5.5 million shares. The 2014 Plan will expire on November 13, 2024. As of December 31, 2018, 2.0 million shares remained available for future issuance under the 2014 Plan. Stock-Based Compensation Expense The Company recognized stock-based compensation expense as follows (in thousands):
In the first quarter of 2016, the Company’s former Chief Financial Officer retired. As the service or performance conditions for her outstanding RSUs had not been satisfied at the time of her departure, the Company reversed previously accrued stock-based compensation expenses of $2.9 million associated with the unvested RSUs and this credit was reflected in selling, general and administrative expenses for the year ended December 31, 2016. RSUs The Company’s RSUs include time-based RSUs, RSUs with performance conditions (“PSUs”), RSUs with market conditions (“MSUs”), and RSUs with both market and performance conditions (“MPSUs”). Vesting of awards with performance conditions or market conditions is subject to the achievement of pre-determined performance goals and the approval of such achievement by the Compensation Committee of the Board of Directors (the “Compensation Committee”). All awards include service conditions which require continued employment with the Company. A summary of RSU activity is presented in the table below (in thousands, except per-share amounts):
The intrinsic value related to vested RSUs was $90.0 million, $74.0 million and $62.9 million for the years ended December 31, 2018, 2017 and 2016, respectively. As of December 31, 2018, the total intrinsic value of all outstanding RSUs was $494.0 million, based on the closing stock price of $116.25. As of December 31, 2018, unamortized compensation expense related to all outstanding RSUs was $124.5 million with a weighted-average remaining recognition period of approximately 3.5 years. Cash proceeds from vested PSUs with a purchase price totaled $10.6 million for the year ended December 31, 2018. There were no December 31, 2017 and 2016. Time-Based RSUs For the years ended December 31, 2018, 2017 and 2016, the Compensation Committee granted 133,000, 81,000 and 133,000 RSUs, respectively, with service conditions to non-executive employees and non-employee directors. The RSUs vest over four years for employees and one year for directors, subject to continued service with the Company.PSUs and MPSUs 2019 PSUs:In October 2018, the Compensation Committee granted 53,000 PSUs to certain non-executive employees, which represent a target number of shares to be earned based on the Company’s 2020 revenue goals for certain regions or product line divisions, or based on the Company’s average two -year (2019 and 2020 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2019 Non-Executive PSUs”). The maximum number of shares that an employee can earn is either 200% or 300% of the target number of the 2019 Non-Executive PSUs, depending on the job classification of the employee. 50% of the 2019 Non-Executive PSUs will vest in the first quarter of 2021 if the pre-determined performance goals are met during the performance period. The remaining 2019 Non-Executive PSUs will vest over the following two years on an annual or quarterly basis. Assuming the achievement of the highest level of performance goals, the total stock-based compensation cost for the 2019 Non-Executive PSUs is $10.9 million.The 2019 Non-Executive PSUs contain a purchase price feature, which requires the employees to pay the Company $30 per share upon vesting of the shares. Shares that do not vest will not be subject to the purchase price payment. The Company determined the grant date fair value of the 2019 Non-Executive PSUs using the Black-Scholes model with the following assumptions: stock price of $108.43, expected term of 2.9 years, expected volatility of 28.7% and risk-free interest rate of 2.9%. 2018 PSUs:In February 2018, the Compensation Committee granted 188,000 PSUs to the executive officers, which represent a target number of shares to be earned based on the Company’s average two -year (2018 and 2019 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2018 Executive PSUs”). The maximum number of shares that an executive officer can earn is 300% of the target number of the 2018 Executive PSUs. 50% of the 2018 Executive PSUs will vest in the first quarter of 2020 if the pre-determined performance goals are met during the performance period. The remaining 2018 Executive PSUs will vest over the following two years on a quarterly basis. Assuming the achievement of the highest level of performance goals, the total stock-based compensation cost for the 2018 Executive PSUs is $46.1 million.In February 2018, the Compensation Committee granted 44,000 PSUs to certain non-executive employees, which represent a target number of shares to be earned based on the Company’s 2019 revenue goals for certain regions or product line divisions, or based on the Company’s average two -year (2018 and 2019 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2018 Non-Executive PSUs”). The maximum number of shares that an employee can earn is either 200% or 300% of the target number of the 2018 Non-Executive PSUs, depending on the job classification of the employee. 50% of the 2018 Non-Executive PSUs will vest in the first quarter of 2020 if the pre-determined performance goals are met during the performance period. The remaining 2018 Non-Executive PSUs will vest over the following two years on an annual or quarterly basis. Assuming the achievement of the highest level of performance goals, the total stock-based compensation cost for the 2018 Non-Executive PSUs, excluding cancelled shares for the terminated employees, is $8.8 million.The 2018 Executive PSUs and the 2018 Non-Executive PSUs contain a purchase price feature, which requires the employees to pay the Company $30 per share upon vesting of the shares. Shares that do not vest will not be subject to the purchase price payment. The Company determined the grant date fair value of the 2018 Executive PSUs and the 2018 Non-Executive PSUs using the Black-Scholes model with the following assumptions: stock price of $110.00, expected term of 2.6 years, expected volatility of 27.5% and risk-free interest rate of 2.3%. 2017 PSUs:In February 2017, the Compensation Committee granted 200,000 PSUs to the executive officers, which represented a target number of shares that would be earned based on the Company’s average two -year (2017 and 2018 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2017 Executive PSUs”). The maximum number of shares that an executive officer could earn was 300% of the target number of the 2017 Executive PSUs. In February 2019, the Compensation Committee approved the revenue achievement for the 2017 Executive PSUs and a total of 521,000 shares were earned by the executive officers. 50% of the 2017 Executive PSUs vested in the first quarter of 2019. The remaining 2017 Executive PSUs vest over the following two years on a quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2017 Executive PSUs is $31.5 million.In February 2017, the Compensation Committee granted 48,000 PSUs to certain non-executive employees, which represented a target number of shares that would be earned based on the Company’s 2018 revenue goals for certain regions or product line divisions, or based on the Company’s average two -year (2017 and 2018 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2017 Non-Executive PSUs”). The maximum number of shares that an employee could earn was either 200% or 300% of the target number of the 2017 Non-Executive PSUs, depending on the job classification of the employee. In February 2019, the Compensation Committee approved the revenue achievement for the 2017 Non-Executive PSUs and a total of 101,000 shares were earned by the employees. 50% of the 2017 Non-Executive PSUs vested in the first quarter of 2019. The remaining 2017 Non-Executive PSUs vest over the following two years on an annual or quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2017 Non-Executive PSUs, excluding cancelled shares for the terminated employees, is $6.1 million.The 2017 Executive PSUs and the 2017 Non-Executive PSUs contain a purchase price feature, which requires the employees to pay the Company $30 per share upon vesting of the shares. Shares that do not vest will not be subject to the purchase price payment. The Company determined the grant date fair value of the 2017 Executive PSUs and the 2017 Non-Executive PSUs using the Black-Scholes model with the following assumptions: stock price of $89.37, expected term of 2.6 years, expected volatility of 28.6% and risk-free interest rate of 1.3%. 2016 PSUs:In February 2016, the Compensation Committee granted 285,000 PSUs to the executive officers, and in July 2016, the Compensation Committee granted 12,000 PSUs to the Company’s new Chief Financial Officer, which represented a target number of shares that would be earned based on the Company’s average two -year (2016 and 2017 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2016 Executive PSUs”). The maximum number of shares that an executive officer could earn was 300% of the target number of the 2016 Executive PSUs. In February 2018, the Compensation Committee approved the revenue achievement for the 2016 Executive PSUs and a total of 651,000 shares were earned by the executive officers. 50% of the 2016 Executive PSUs vested in the first quarter of 2018. The remaining 2016 Executive PSUs vest over the following two years on a quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2016 Executive PSUs, excluding cancelled shares for the Company’s former Chief Financial Officer, is $26.1 million.In February 2016, the Compensation Committee granted 64,000 PSUs to certain non-executive employees, which represented a target number of shares that would be earned based on the Company’s 2017 revenue goals for certain regions or product line divisions, or based on the Company’s average two -year (2016 and 2017 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2016 Non-Executive PSUs”). The maximum number of shares that an employee could earn was either 200% or 300% of the target number of the 2016 Non-Executive PSUs, depending on the job classification of the employee. In February 2018, the Compensation Committee approved the revenue achievement for the 2016 Non-Executive PSUs and a total of 128,000 shares were earned by the employees. 50% of the 2016 Non-Executive PSUs vested in the first quarter of 2018. The remaining 2016 Non-Executive PSUs vest over the following two years on an annual or quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2016 Non-Executive PSUs, excluding cancelled shares for the terminated employees, is $5.1 million.The 2016 Executive PSUs and the 2016 Non-Executive PSUs contain a purchase price feature, which requires the employees to pay the Company $20 per share upon vesting of the shares. Shares that do not vest will not be subject to the purchase price payment. The Company determined the grant date fair value of the 2016 Executive PSUs and the 2016 Non-Executive PSUs granted in February 2016 using the Black-Scholes model with the following assumptions: stock price of $58.98, expected term of 2.6 years, expected volatility of 31.1% and risk-free interest rate of 0.9%. For the 2016 Executive PSUs granted in July 2016, the Company used the following assumptions: stock price of $70.98, expected term of 2.3 years, expected volatility of 29.6% and risk-free interest rate of 0.7%. 2015 PSUs: In February 2015, the Compensation Committee granted 172,000 PSUs to the executive officers, which represented a target number of shares that would be earned based on the Company’s average two -year (2015 and 2016 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2015 Executive PSUs”). The maximum number of shares that an executive officer could earn was 300% of the target number of the 2015 Executive PSUs. In February 2017, the Compensation Committee approved the revenue achievement for the 2015 Executive PSUs and a total of 432,000 shares were earned by the executive officers. 50% of the 2015 Executive PSUs vested in the first quarter of 2017. The remaining 2015 Executive PSUs vest over the following two years on a quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2015 Executive PSUs, excluding cancelled shares for the Company’s former Chief Financial Officer, is $21.0 million.In February 2015, the Compensation Committee granted 58,000 PSUs to certain non-executive employees, which represented a target number of shares that would be earned based on the Company’s 2016 revenue goals for certain regions or product line divisions, or based on the Company’s average two -year (2015 and 2016 ) revenue growth rate compared against the analog industry’s average two -year revenue growth rate as published by the Semiconductor Industry Association (“2015 Non-Executive PSUs”). The maximum number of shares that an employee could earn was either 200% or 300% of the target number of the 2015 Non-Executive PSUs, depending on the job classification of the employee. In February 2017, the Compensation Committee approved the revenue achievement for the 2015 Non-Executive PSUs and a total of 118,000 shares were earned by the employees. 50% of the 2015 Non-Executive PSUs vested in the first quarter of 2017. The remaining 2015 Non-Executive PSUs vest over the following two years on an annual or quarterly basis. Based on the actual achievement of the performance goals, the total stock-based compensation cost for the 2015 Non-Executive PSUs, excluding cancelled shares for the terminated employees, is $5.7 million.2015 MPSUs:In December 2015, the Compensation Committee granted 86,000 MPSUs to the executive officers and 41,000 MPSUs to certain non-executive employees, which represent a target number of shares to be earned upon achievement of both market conditions and performance conditions (“2015 MPSUs”). The maximum number of shares that an employee can earn is 500% of the target number of the 2015 MPSUs. The 2015 MPSUs consist of four separate tranches with various performance periods all ending on December 31, 2019. The first tranche contains market conditions only, which require the achievement of five stock price targets ranging from $71.36 to $95.57 with a performance period from January 1, 2016 to December 31, 2019. The second, third and fourth tranches contain both market and performance conditions. The five stock price targets for the second tranche range from $89.56 to $106.81 with a performance period from January 1, 2017 to December 31, 2019. The five stock price targets for the third tranche range from $120.80 to $135.48 with a performance period from January 1, 2018 to December 31, 2019. The five stock price targets for the fourth tranche range from $126.08 to $136.79 with a performance period from January 1, 2019 to December 31, 2019. In addition, each of the second, third and fourth tranches requires the achievement of one of following six operating metrics:
The following table summarize the status of the market and performance conditions:
A total of 394,000 shares have been earned by the employees as of December 31, 2018. The 2015 MPSUs will vest on January 1, 2020, with post-vesting sales restrictions on the vested shares for up to an additional two years.The Company determined the grant date fair value of the 2015 MPSUs using a Monte Carlo simulation model with the following weighted-average assumptions: stock price of $61.35, expected volatility of 33.2%, risk-free interest rate of 1.3%, and an illiquidity discount of 7.8% to account for the post-vesting sales restrictions. Assuming the achievement of all of the required market and performance goals, the total stock-based compensation cost for the 2015 MPSUs, excluding cancelled shares for the terminated employees, is $24.6 million ($8.3 million for the first tranche, $4.5 million for the second tranche, $5.2 million for the third tranche, and $6.6 million for the fourth tranche).For the first tranche which contains market conditions only, stock-based compensation expense is being recognized over the requisite service period. For the second, third and fourth tranches, stock-based compensation expense for each tranche is recognized if an operating metric has been achieved, or if management believes it is probable that an operating metric will be achieved during the performance periods. As of December 31, 2018, two operating metrics have been achieved, and based on management’s quarterly assessment, one additional operating metric was considered probable of being achieved during the performance period. Accordingly, stock-based compensation expense is being recognized for the second, third and fourth tranches over the requisite service period.MSUs 2018 MSUs:In October 2018, the Compensation Committee granted 60,000 MSUs to the executive officers and 60,000 MSUs to certain non-executive employees, which represent a target number of shares to be earned upon achievement of stock price targets (“2018 MSUs”). The maximum number of shares that an employee can earn is 500% of the target number of the 2018 MSUs if the Company achieves five stock price targets ranging from $140 to $172. The performance period for the first two stock price targets is from October 26, 2018 to December 31, 2021, and the performance period for the last three price targets is from October 26, 2018 to December 31, 2023. As of December 31, 2018, none of the stock price targets has been met. If the stock price targets are achieved during the performance periods, the 2018 MSUs will vest on January 1, 2024, with post-vesting sales restrictions on the vested shares for up to an additional two years. The total stock-based compensation cost for the 2018 MSUs is $41.1 million.The Company determined the grant date fair value of the 2018 MSUs using a Monte Carlo simulation model with the following assumptions: stock price of $108.43, expected volatility of 31.6%, a risk-free interest rate of 3.0%, and an illiquidity discount of 8.7% to account for the post-vesting sales restrictions. 2013 MSUs:In December 2013, the Compensation Committee granted 276,000 MSUs to the executive officers and 84,000 MSUs to certain non-executive employees, which represented a target number of shares that would be earned upon achievement of stock price targets (“2013 MSUs”). The maximum number of shares that an employee could earn was 500% of the target number of the 2013 MSUs if the Company achieved five price targets ranging from $40 to $56 during a performance period from January 1, 2014 to December 31, 2018. As of December 31, 2015, all stock price targets have been met and the employees earned a total of 1.8 million shares. The 2013 MSUs will vest quarterly from January 1, 2019 to December 31, 2023. The total stock-based compensation cost for the 2013 MSUs, excluding cancelled shares for the terminated employees, is $38.2 million.The Company determined the grant date fair value of the 2013 MSUs using a Monte Carlo simulation model with the following assumptions: stock price of $31.73, expected volatility of 38.7% and a risk-free interest rate of 1.6%. There was no illiquidity discount because the awards do not contain any post-vesting sales restrictions.Stock Options A summary of stock option activity is presented in the table below:
Total intrinsic value of options exercised was $0.5 million, $0.7 million and $3.7 million for the years ended December 31, 2018, 2017 and 2016, respectively. Cash proceeds from stock option exercises were $0.1 million, $0.1 million and $1.3 million for the years ended December 31, 2018, 2017 and 2016, respectively.Employee Stock Purchase Plan (“ESPP”) Under the ESPP, eligible employees may purchase common stock through payroll deductions. Participants may not purchase more than 2,000 shares in a six -month offering period, or purchase shares having a value greater than $25,000 in any calendar year as measured at the beginning of the offering period in accordance with the Internal Revenue Code and applicable Treasury Regulations. The ESPP provides for an annual increase by an amount equal to the least of 1.0 million shares, 2% of the outstanding shares of common stock on the first day of the year, or a number of shares as determined by the Board of Directors. As of December 31, 2018, 4.6 million shares were available for future issuance. The ESPP will expire in November 2024. For the years ended December 31, 2018, 2017 and 2016, 33,000, 40,000 and 53,000 shares, respectively, were issued under the ESPP. The intrinsic value of the shares issued was $1.1 million, $1.0 million and $1.0 million for the years ended December 31, 2018, 2017 and 2016, respectively. The unamortized expense as of December 31, 2018 was $0.1 million, which will be recognized through the first quarter of 2019. The Black-Scholes model was used to value the employee stock purchase rights with the following weighted-average assumptions:
Cash proceeds from the shares issued under the ESPP were $3.0 million, $2.7 million and $2.5 million for the years ended December 31, 2018, 2017 and 2016, respectively. |