v3.20.2

Stockholders' Equity - Common Stock and Stock-based Compensation (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Aug. 06, 2020 USD ($) shares	Jun. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($) shares	Sep. 30, 2020 USD ($) plan shares	Sep. 30, 2019 USD ($) shares	Mar. 31, 2020 shares	Jan. 01, 2020 shares	Dec. 31, 2019 shares	Jun. 30, 2019 shares	Mar. 31, 2019 shares	Jan. 01, 2019 shares	Dec. 31, 2018 shares
Stockholders' Equity
Proceeds from issuance of common stock, net of offering costs | $	$ 299,800			$ 299,796	$ 0
Authorized shares of capital stock (in shares)				205,000,000
Authorized shares of common stock (in shares)				200,000,000				200,000,000
Authorized shares of preferred stock (in shares)				5,000,000				5,000,000
Common stock, outstanding (in shares)				71,294,706				63,569,109
Available shares of common stock reserved for future issuance (in shares)				26,355,976
Number of stock-based compensation plans | plan				2
Issuance of common stock in connection with employee stock purchase plan | $		$ 1,771	$ 1,895
Common Stock
Stockholders' Equity
Sale of common stock (in shares)	6,800,000
Common stock, outstanding (in shares)		64,300,599	63,388,705	71,294,706	63,388,705	63,703,067		63,569,109	63,231,376	58,189,318		57,968,493
Issuance of common stock in connection with employee stock purchase plan (in shares)		83,573	54,485	83,573
Issuance of common stock in connection with employee stock purchase plan | $				$ 1,800
Restricted Stock Units (RSUs)
Stockholders' Equity
Available shares of common stock reserved for future issuance (in shares)				3,431,829
Performance restricted stock units
Stockholders' Equity
Available shares of common stock reserved for future issuance (in shares)				1,760,164
Stock options
Stockholders' Equity
Available shares of common stock reserved for future issuance (in shares)				4,023,741
Convertible debt securities
Stockholders' Equity
Available shares of common stock reserved for future issuance (in shares)				17,140,242
Employee Stock
Stockholders' Equity
Available shares of common stock reserved for future issuance (in shares)				729,391
Equity Incentive Plan 2014
Stockholders' Equity
Increase in shares in available for future issuance							3,175,011				2,896,365

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