Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock option assumptions

We used the following assumptions to apply the Black-Scholes option-pricing model to stock options granted during the years ended December 31, 2019 and 2018:

	Year Ended   December 31,
	2019	2018
Expected dividend yield	0.00%	0.00%
Risk-free interest rate	2.62%	2.62%
Expected term (in years)	7.94	7.94
Volatility	81%	81%

Stock option activity

The following table summarizes stock option activity:

	Number of Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
							(in thousands)
Outstanding, December 31, 2018	4,808,390	$	15.90	8.09			$	129
Granted	94,295	$	13.58	9.07	$	3.11
Exercised	(2,143)	$	1.85				$	20
Forfeited	(596,233)	$	15.85		$	3.48
Outstanding, December 31, 2019	4,304,309	$	15.86	7.08			$	242
Exercised	(922,770)	$	14.76				$	28,022
Forfeited	(115,191)	$	19.19		$	3.54
Outstanding, December 31, 2020	3,266,348	$	16.06	5.82			$	94,962
Exercisable, December 31, 2020	3,266,348	$	16.06	5.82			$	94,962
Vested, December 31, 2020	3,266,348	$	16.06	5.82			$	94,962
Non-vested, December 31, 2019	964,396				$	3.52
Non-vested, December 31, 2020	—				$	—

Restricted stock unit activity

The following table summarizes restricted stock unit activity:

	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Outstanding, December 31, 2018	—	$	—
Granted	1,431,555	$	11.93
Forfeited	(5,416)	$	12.00
Outstanding, December 31, 2019	1,426,139	$	11.93
Granted	1,141,413	$	11.98
Vested	(463,762)	$	11.89
Forfeited	(44,606)	$	12.31
Outstanding, December 31, 2020	2,059,184	$	11.95