STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2015

Stock-based compensation

Schedule of assumptions used to calculate the fair value of option grants

        The Company used the following assumptions to calculate the fair value of option grants for the years ended December 31, 2015, 2014 and 2013.

	2015	2014	2013
Employee and Director Stock Options
Risk-free interest rate	1.04 - 1.59%	1.26 - 1.51%	0.67 - 1.38%
Dividend yield	None	None	None
Expected option term (in years)	4.30 - 4.31	4.33 - 4.41	4.48 - 4.51
Expected stock price volatility	44.78 - 50.45%	42.6 - 49.0%	49.2 - 63.5%

Schedule of assumptions used to calculate the fair value of stock purchase rights granted under the ESPP

        The Company used the following assumptions to calculate the fair value of stock purchase rights granted under the ESPP for the years ended December 31, 2015, 2014 and 2013:

	2015	2014	2013
Employee Stock Purchase Plan
Risk-free interest rate	0.07 - 0.41%	0.06 - 0.08%	0.08 - 0.10%
Dividend yield	None	None	None
Expected option term (in years)	0.5	0.5	0.5
Expected stock price volatility	42.7 - 58.2%	44.8 - 61.4%	28.8 - 35%

Schedule of stock-based compensation expense recognized for stock options, stock awards, restricted stock units and the Company's condensed consolidated employee stock purchase program (ESPP)

        The following table presents stock-based compensation expense recognized for stock options, restricted stock units and the ESPP in the Company's Statements of Operations (in thousands):

	2015		2014		2013
Cost of sales	$	21	$	14	$	42
Research and development expense		277		258		364
Selling, general and administrative expense		13,930		8,658		5,702
Total	$	14,228	$	8,930	$	6,108

The 2004 Plan

Stock-based compensation

Summary of the options activity under the plan

	Shares			Weighted- Average Exercise Price
Options outstanding at December 31, 2014		6,002,334		$	7.84
Options granted		—			—
Options exercised		(1,098,790	)		6.68
Options forfeited		(201,392	)		9.43
Options expired		(3,354	)		6.66
Options outstanding at December 31, 2015		4,698,798		$	8.05
Options vested and expected to vest at December 31, 2015		4,577,274		$	7.96
Options exercisable at December 31, 2015		3,536,763		$	7.32

	Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at December 31, 2015		6.46	$	47,370
Options vested and expected to vest at December 31, 2015		6.42	$	46,561
Options exercisable at December 31, 2015		6.06	$	38,241

Schedule of restricted stock units

	Number of Shares			Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Contractual Term (In years)
Non-vested restricted stock units at December 31, 2014		521,286		$	8.67
Granted		—			—
Vested		(218,404	)		9.26
Forfeited		(33,768	)		10.54
Non-vested restricted stock units at December 31, 2015		269,114		$	10.90		1.27

The 2014 Plan

Stock-based compensation

Summary of the options activity under the plan

	Shares			Weighted Average Exercise Price
Options outstanding at December 31, 2014		745,672		$	13.42
Options granted		1,990,025			19.09
Options exercised		(42,555	)		12.12
Options forfeited		(169,521	)		18.16
Options expired		(1,396	)		14.77
Options outstanding at December 31, 2015		2,522,225		$	17.59
Options vested and expected to vest at December 31, 2015		2,051,327		$	17.37
Options exercisable at December 31, 2015		527,313		$	15.96

	Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at December 31, 2015		8.95	$	3,640
Options vested and expected to vest at December 31, 2015		8.91	$	3,211
Options exercisable at December 31, 2015		8.64	$	1,220

Schedule of restricted stock units

	Number of Shares			Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Contractual Term (In years)
Non-vested restricted stock units at December 31, 2014		23,178		$	15.53
Granted		522,216		$	18.27
Vested		(121,429	)		17.21
Forfeited		(12,850	)		18.16
Non-vested restricted stock units at December 31, 2015		411,115		$	18.43		1.57