Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Stockholders Equity Note [Abstract]

Schedule of Share-based Compensation, Fair Value of Stock-Based Compensation Granted

The following table represents the fair value of stock-based compensation granted during the year ended 2021 (in thousands):

	Fair Value
Stock options	$	12,309
RSUs		6,661
Restricted stock		466
Total stock-based compensation expense	$	19,436

Schedule of Compensation Cost

The Company recorded stock-based compensation expense by award as follows (in thousands):

	Years Ended
	2021		2020		2019
Employee stock option	$	10,373	$	9,577	$	8,144
Restricted stock		616		428		320
RSUs		2,667		1,732		1,905
PSUs		371		147		—
Nonemployee stock options		578		262		178
Total stock-based compensation expense	$	14,605	$	12,146	$	10,547

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The Company recorded stock-based compensation expense in the following categories (in thousands):

	Years Ended
	2021		2020		2019
Cost of sales	$	215	$	112	$	52
General and administrative		6,495		4,925		4,010
Selling and marketing		3,454		3,471		3,318
Research and development		4,441		3,638		3,167
Total stock-based compensation expense, net		14,605		12,146		10,547
Amounts capitalized as part of inventory		1,295		1,129		1,017
Total stock-based compensation expense, gross	$	15,900	$	13,275	$	11,564

Schedule of Unrecognized Compensation Cost, Non-Vested Stock-Based Compensation Arrangements

As of December 31, 2021, total unrecognized compensation cost related to non-vested stock-based compensation arrangements granted under the Plan were as follows (in thousands):

	2021
Stock options	$	12,682
Restricted stock, RSUs and PSUs		6,981
Total unrecognized stock-based compensation cost	$	19,663

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The risk-free rate is based on the U.S. Treasury yield curve corresponding to the expected term at the time of the grant.

	Years Ended
	2021			2020			2019
Expected dividend yield		0	%		0	%		0	%
Expected volatility		53	%		53	%		53	%
Risk-free interest rate		0.84	%		0.53	%		2.40	%
Expected term (in years)		5.38			5.72			5.66

Schedule of Share-based Compensation, Stock Options, Activity

A summary of option activity under the Plan for the year ended December 31, 2021 was as follows:

	Shares (in 000’s)			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in 000’s)
Outstanding at January 1, 2021		3,418		$	19.80
Granted		273			95.32
Exercised		(1,206	)		16.12
Forfeited or expired		(50	)		33.77
Outstanding at December 31, 2021		2,435		$	29.81		6.34	$	151,033
Exercisable at December 31, 2021		1,863		$	20.54		5.75	$	131,837

Share-based Compensation, Performance Shares Award Unvested Activity

A summary of unvested options activity under the Plan for the year ended December 31, 2021 was as follows:

	Shares (in 000’s)			Weighted-Average Grant-Date Fair Value
Unvested at January 1, 2021		1,046		$	15.09
Granted		273			45.08
Forfeited or expired		(50	)		7.89
Vested		(697	)		15.74
Unvested at December 31, 2021		572		$	28.63

Summary of Weighted Average Grant Date Fair Value of Options Granted and Total intrinsic Value of options Exercised

The weighted average grant date fair value of options granted and the total intrinsic value of options exercised were as follows:

	Years Ended
	2021		2020		2019
Weighted-average grant-date fair value	$	45.08	$	13.85	$	17.95
Intrinsic value of options (in thousands)	$	127,024	$	59,771	$	9,955

Schedule of Share-based Compensation, Restricted Stock, RSU and PSU Activity

A summary of restricted stock, RSU and PSU activity under the Plan for the year ended December 31, 2021 was as follows:

	Restricted Stock					Restricted Stock Units					Performance Stock Units
	Units (in 000’s)			Weighted- Average Grant- Date Fair Value		Units (in 000’s)			Weighted- Average Grant- Date Fair Value		Units (in 000’s)			Weighted- Average Grant- Date Fair Value
Outstanding at January 1, 2021		11		$	59.06		122		$	32.97		15		$	51.42
Granted		3			148.36		63			105.62		—			—
Vested		(11	)		59.95		(54	)		35.34		(5	)		51.42
Outstanding at December 31, 2021		3		$	154.96		131		$	66.94		10		$	51.42