Note 5 - Stock Options and Restricted Stock Awards

9 Months Ended

Sep. 30, 2018

Notes to Financial Statements

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

5

–

Stock Options and Restricted Stock Awards

Valuation and Expense Information

The Company accounts for stock-based compensation in accordance with ASC

718

-

10,

“Compensation – Stock Compensation,”

which requires the measurement and recognition of compensation expense for all share-based payment awards made to our employees and directors, including employee stock options, restricted stock unit awards and employee stock purchases related to the Employee Stock Purchase Plan based on estimated fair values.

Stock-based compensation expense, calculated using the Black-Scholes option-pricing model for employee stock options and included in selling, general and administrative expense, was

$2.0

million for the

three

months ended

September 30, 2018,

and

$3.4

million for the

three

months ended

September 30, 2017.

Stock-based compensation expense for the

nine

months ended

September 30, 2018

was

$15.8

million and for the

nine

months ended

September 30, 2017

was

$12.0

million.

The Company recorded excess tax benefits of

$92,000

in the

three

months ended

September 30, 2018

and

$1.9

million in the

three

months ended

September 30, 2017

and excess tax benefits of

$0.3

million in the

nine

months ended

September 30, 2018

and

$3.9

million in the

nine

months ended

September 30, 2017.

As of

September 30, 2018,

the Company had

$9.0

million of unrecognized compensation expense related to non-vested employee stock options to be recognized over a weighted-average period of

3.4

years and

$8.2

million of unrecognized compensation cost related to non-vested restricted stock units to be recognized over a weighted-average period of

2.1

years.