STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2014

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

Summary of Black-Scholes Valuation Model used to Determine Fair Value of Stock Options

The Black-Scholes model requires the input of highly subjective assumptions, which are summarized in the table below for the years ended December 31:

	2014	2013	2012
Expected dividend yield	—	—	—
Expected stock price volatility	67%	83%	82%
Risk-free interest rate	1.3%	0.9%	0.5%
Expected life of options in years	4.0	4.4	1.5 - 5

Schedule of Stock-based Compensation

Our stock-based compensation for the years ended December 31 was as follows (in thousands):

	2014		2013		2012
Stock-based compensation by type of award:
Stock options	$	994	$	1,289	$	1,527
Restricted stock units	484		124		18
Employee stock purchase plan	48		20		20
	$	1,526	$	1,433	$	1,565
Stock-based compensation by category of expense:
Cost of goods sold	$	40	$	52	$	68
Research, development and engineering	181		254		308
Selling, general and administrative	1,305		1,127		1,189
	$	1,526	$	1,433	$	1,565