Changes in Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2021

Stockholders Equity Note [Abstract]

Summary of Changes in Stockholders' Equity

The following tables summarize the changes in stockholders’ equity for the three months ended March 31, 2021 and 2020.

	Common Stock, $0.001 Par Value					Treasury Stock, $0.001 Par Value				Additional Paid-In			Accumulated Other Comprehensive			Accumulated
	Shares			Amount		Shares		Amount		Capital			Income			Deficit			Total
Balances at December 31, 2020		46,115		$	46		12	$	—	$	1,241,167		$	4,603		$	(483,161	)		762,655
Issuance of common stock under stock plans, net of shares withheld    for employee taxes		482			1		—		—		6,582			—			—			6,583
Stock-based compensation		—			—		—		—		32,947						—			32,947
Equity component of the 2022 Notes conversions		363			—		—		—		(2,307	)		—			—			(2,307	)
Settlement of Convertible Note Hedges		(364	)		—		364		—		724			—			—			724
Cumulative translation adjustment		—			—		—		—		—			(2,489	)		—			(2,489	)
Unrealized loss on investments, net of    income taxes of ($36)		—			—		—		—		—			(240	)		—			(240	)
Net loss		—			—		—		—		—			—			(23,159	)		(23,159	)
Balances at March 31, 2021		46,596		$	47		376	$	-	$	1,279,113		$	1,874		$	(506,320	)	$	774,714

	Common Stock, $0.001 Par Value				Additional Paid-In		Accumulated Other Comprehensive			Accumulated
	Shares		Amount		Capital		(Loss)			Deficit			Total
Balances at December 31, 2019		42,955	$	44	$	1,048,380	$	(336	)	$	(398,130	)		649,958
Issuance of common stock under stock plans, net of shares withheld for employee taxes		411		—		1,320		—			—			1,320
Stock-based compensation		—		—		27,905					—			27,905
Cumulative translation adjustment		—		—		—		(1,077	)		—			(1,077	)
Unrealized gain on investments, net of income taxes of $0		—		—		—		583			—			583
Net loss		—		—		—		—			(17,716	)		(17,716	)
Balances at March 31, 2020		43,366	$	44	$	1,077,605	$	(830	)	$	(415,846	)	$	660,973