Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Summary of Stock Option Activity

A summary of the stock option activity under the Company’s plans for the nine months ended September 30, 2021 is as follows:

 

	Number of Shares	Weighted Average Exercise Price
Options outstanding at December 31, 2020	3,785,941	$	15.21
Options granted	887,332	$	48.19
Less:
Options exercised	931,954	$	10.85
Options forfeited	226,411	$	31.73
Options outstanding at September 30, 2021	3,514,908	$	23.63
Exercisable at September 30, 2021	1,758,830	$	12.07

Summary of Fair Value of Each Stock Option Award Granted

The fair value of each stock option award granted during the nine months ended September 30, 2021 was estimated as of the grant date using a Black-Scholes model with the following weighted average assumptions:

	Nine Months Ended September 30, 2021
Expected term (in years)	3.5 - 5.5
Risk-free interest rate (%)	0.7%
Expected volatility (%)	39% - 49%
Dividend yield (%)	—
Weighted average fair value/share at grant date	$18.19

Summary of Restricted Stock Activity

A summary of the restricted stock activity under the Company’s plans for the nine months ended September 30, 2021 is as follows:

	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Nonvested at December 31, 2020	291,891	$	23.82
Granted	345,416	$	47.92
Vested	(111,646)	$	23.28
Forfeited	(32,885)	$	35.23
Nonvested at September 30, 2021	492,776	$	40.08

Share-based Payment Arrangement, Performance Shares, Activity

The following table summarizes the performance-based stock awards as of September 30, 2021:

	Number of Performance Shares	Weighted Average Grant Date Fair Value
Nonvested at December 31, 2020	—	$	—
Granted	356,548	$	44.87
Vested	—	$	—
Forfeited	—	$	—
Nonvested at September 30, 2021	356,548	$	44.87