Employee Equity-Based Compensation

3 Months Ended

Mar. 31, 2018

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

Employee Equity-Based Compensation

NOTE 13. EMPLOYEE EQUITY-BASED COMPENSATION

The following table summarizes option activity under all plans during the three-month period ended March 31, 2018:

	Number of Shares		Weighted Average Exercise Price per Share
Options Outstanding January 1, 2018	7,328,131		$	10.16
Granted	920,439		26.08
Forfeited	(120,212	)	9.25
Exercised	(44,290	)	18.31
Expired	(352	)	24.45
Options Outstanding March 31, 2018	8,083,716		11.94

The table below summarizes the resulting weighted average inputs used to calculate the estimated fair value of options awarded during the periods shown below:

	Three Months Ended
	March 31,			March 31,
	2018			2017
Expected term (in years)	6.11			6.19
Volatility	68		%	79		%
Expected dividends	—			—
Risk free interest rates	2.69		%	2.07		%
Weighted average fair value	$	16.25		$	16.84

The following table shows summary information for outstanding options and options that are exercisable (vested) as of March 31, 2018:

	Options Outstanding		Options Exercisable
Number of options	8,083,716		5,667,598
Weighted average remaining contractual term (in years)	6.35		5.32
Weighted average exercise price	$	11.94	$	7.86
Weighted average fair value	$	8.46	$	5.59
Aggregate intrinsic value (in thousands)	$	93,003	$	86,184

The following table summarizes restricted stock unit and restricted stock award activity during the three-month period ending March 31, 2018:

	Number of Shares		Weighted Average Grant Date Fair Value per Share
Outstanding January 1, 2018	24,150		$	26.45
Granted	—		—
Forfeited	—		—
Vested/released	(8,050	)	26.45
Outstanding March 31, 2018	16,100		26.45

Equity-based compensation is summarized below (in thousands):

	Three Months Ended
	March 31,		March 31,
	2018		2017
Cost of sales	$	46	$	—
Research and development	1,612		726
Sales, general and administrative	3,944		2,489
Equity-based compensation expense	$	5,602	$	3,215

As of March 31, 2018, $451,000 and $81,000 of equity-based compensation expense was a component of capitalized inventory and property and equipment, respectively.

As of March 31, 2018, unrecognized equity-based compensation cost related to unvested stock options and unvested restricted stock units was $24.3 million and $135,000, respectively. This is expected to be recognized over the years 2018 through 2023.