Employee and Consultant Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

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

Stock Option Activity

The following table summarizes option activity under all plans during the years ending December 31, 2016, and December 31, 2015 and shows the exercisable shares as of December 31, 2016:

Stock Option Activity
	Number of Shares		Weighted Average Exercise Price per Share
Options Outstanding January 1, 2015	5,628,726		$	5.20
Granted	717,833		20.59
Forfeited	(54,505	)	11.71
Exercised	(124,884	)	6.44
Expired	—		—
Options Outstanding December 31, 2015	6,167,170		6.91
Granted	1,024,050		14.05
Forfeited	(147,663	)	18.43
Exercised	(158,743	)	7.47
Expired	(27,690	)	4.87
Options Outstanding December 31, 2016	6,857,124		7.72
Exercisable December 31, 2016	4,566,005		4.94

Black-Scholes Assumptions for Option Granted

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

Black-Scholes Assumptions for Option Granted
	12 months			12 months			12 months
	12/31/2016			12/31/2015			12/31/2014
Expected term (in years)	6.43			6.26			6.25
Volatility	86		%	91		%	96		%
Expected dividends	—			—			—
Risk free interest rates	1.6		%	1.7		%	1.9		%
Estimated forfeitures	8.5		%	5.6		%	0.4		%
Weighted average fair value	$	10.35		$	16.69		$	12.63

Stock Option Supplemental Information

The following table shows summary information for outstanding options, options that are exercisable (vested) and outstanding options that are either vested or expected to vest as of December 31, 2016:

Stock Option Supplemental Information
	Options Outstanding		Options Exercisable		Options Vested and Expected to Vest
Number of options	6,857,124		4,566,005		6,711,021
Weighted average remaining contractual term (in years)	6.57		5.83		6.52
Weighted average exercise price	$	7.72	$	4.94	$	7.55
Weighted average fair value	$	5.95	$	3.72	$	5.82
Aggregate intrinsic value (in millions)	$	82.0	$	70.4	$	81.6

Restricted Stock Activity

The following table summarizes restricted stock unit activity during the years ending December 31, 2016, and December 31, 2015:

Restricted Stock Unit (RSU) Activity
	Number of Shares	Weighted Average Grant Date Fair Value per Share
RSU's outstanding January 1, 2015	—	—
Granted	40,250	20.91
Forfeited	—	—
Vested/released	—	—
RSU's outstanding December 31, 2015	40,250	20.91
Granted	—	—
Forfeited	—	—
Vested/released	—	—
RSU's outstanding December 31, 2016	40,250	20.91

Equity-Based Compensation Expense and Tax Benefit

The expense and tax benefits recognized on Company’s Statements of Operations and Comprehensive Loss related to options is summarized below (in thousands):

Equity-Based Compensation Expenses and Tax Benefit (in thousands)
	12 months		12 months		12 months
	12/31/2016		12/31/2015		12/31/2014
Research and development	$	1,585	$	2,479	$	4,334
Sales, general and administrative	7,190		5,909		5,290
Equity-based compensation expense	8,775		8,388		9,624
Recognized tax benefit	$	—	$	—	$	—

Summary of ESPP Activity

A summary of ESPP activity for the year ended December 31, 2016 is as follows:

Shares issued	11,093
Weighted average fair value	20.40
Employee purchases (in thousands)	226