Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

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

Stock-Based Compensation

Note 4 Stock-Based Compensation

Total stock-based compensation expense recognized in our unaudited condensed consolidated statements of operations and comprehensive income (loss) includes amounts related to stock options, restricted stock, and employee stock purchase plans and was as follows (in thousands):

	Quarter Ended March 31,
	2018		2017
Total stock-based compensation expense	$	1,157	$	1,434

The fair value of options granted determined using the Black-Scholes model used the following weighted-average assumptions:

	Quarter Ended March 31,
	2018		2017
Expected dividend yield	0	%	0	%
Risk-free interest rate	2.48	%	2.23	%
Expected life (years)	4.1		6.8
Volatility	35	%	38	%

The total stock-based compensation amounts for 2018 and 2017 disclosed above are recorded in their respective line items within operating expenses in the unaudited condensed consolidated statements of operations and comprehensive income (loss). Included in the expense for the three months ended March 31, 2018 and 2017 was stock compensation expense recorded in the first quarter of 2018 and 2017 related to our 2017 and 2016 incentive bonuses paid in fully vested restricted stock units, which were authorized and granted in the first quarter of 2018 and 2017, respectively.

As of March 31, 2018, $3.1 million of total unrecognized compensation cost, net of estimated forfeitures, related to stock awards. The unrecognized compensation cost is expected to be recognized over a weighted-average period of approximately 3 years.