Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation

v3.8.0.1
Stock-Based Compensation
 9 Months Ended
Sep. 30, 2017
Share-based Compensation [Abstract]  
Stock-Based Compensation
STOCK-BASED COMPENSATION
The Company's Stock Incentive Plan (the "Plan") allows for grants of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units and other stock-based or cash-based awards. The majority of all stock options and restricted stock unit grants outstanding under the Plan were granted in the first quarter of each fiscal year. Stock compensation is recognized based on an estimated number of awards that are expected to vest.
Stock-based compensation expense consisted of the following (in thousands):
 
Three Months Ended September 30,
 
Nine Months Ended September 30,
 
2017
 
2016
 
2017
 
2016
Stock options
$
834

 
$
1,008

 
$
2,843

 
$
2,989

Restricted stock units
1,724

 
1,993

 
5,434

 
5,465

Total
$
2,558

 
$
3,001

 
$
8,277

 
$
8,454


Stock Options
The Company estimates the fair value of stock options using the Black-Scholes model. Key inputs and assumptions used to estimate the fair value of stock options include the exercise price of the award, the expected option term, the expected stock price volatility of the Company's 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 following table presents the weighted average assumptions for stock options granted in the periods:
 
Three Months Ended September 30,
 
Nine Months Ended September 30,
 
2017
 
2016
 
2017
 
2016
Expected option term
4.35 years
 
4.37 years
 
4.54 years
 
4.63 years
Expected stock price volatility
28.79%
 
29.34%
 
28.91%
 
29.80%
Risk-free interest rate
1.68%
 
0.94%
 
1.72%
 
1.17%
Expected annual dividend yield
1.23%
 
1.17%
 
1.30%
 
1.20%
Weighted average grant date fair value
$13.47
 
$13.12
 
$13.03
 
$13.38

During the nine months ended September 30, 2017 and 2016, the Company granted a total of 528,477 and 428,500 stock options, respectively. At September 30, 2017, unrecognized costs related to outstanding stock options totaled approximately $7,927,000, before any related tax benefit. The unrecognized costs related to stock options are amortized over the related vesting period using the straight-line attribution method. Unrecognized costs related to stock options at September 30, 2017 are expected to be recognized over a weighted average period of 2.56 years.
Restricted Stock Units
The Company estimates the fair value of service-based and performance-based restricted stock units using the Black-Scholes model. Key inputs and assumptions used to estimate the fair value of restricted stock units include the vesting period, expected annual dividend yield and closing price of the Company's common stock on the date of grant.
 The following table presents the weighted average assumptions for restricted stock units granted in the periods:
 
Three Months Ended September 30,
 
Nine Months Ended September 30,
 
2017
 
2016
 
2017
 
2016
Vesting period
4.03 years
 
4.01 years
 
3.87 years
 
3.83 years
Expected annual dividend yield
1.23%
 
1.17%
 
1.30%
 
1.16%
Estimated average grant date fair value per restricted stock unit
$55.61
 
$55.43
 
$52.65
 
$55.94

During the nine months ended September 30, 2017 and 2016, the Company granted 255,032 and 190,119 restricted stock units, respectively. At September 30, 2017, unrecognized costs related to outstanding restricted stock units totaled approximately $15,852,000, before any related tax benefit. The unrecognized costs related to restricted stock units are being amortized over the related vesting period using the straight-line attribution method. These unrecognized costs at September 30, 2017 are expected to be recognized over a weighted average period of 2.47 years.