Net Loss per Share - Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss used to compute net loss per share, basic and diluted	$ (229,743)	$ (124,827)	$ (128,154)
Denominator:
Weighted-average number of shares used in computing net loss per share, basic and diluted	81,011	69,555	57,848
Net loss per share, basic and diluted (in dollars per share)	$ (2.84)	$ (1.79)	$ (2.22)
Potentially dilutive shares not included in diluted per share calculation	18,343	10,933	10,589
Convertible Notes
Denominator:
Convertible, If-converted value in excess of principal	$ 388,400
Potentially dilutive shares not included in diluted per share calculation	7,411

Net income loss available to common stockholders, basic and diluted.

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
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- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031898-161870

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- Definition

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=117326831&loc=d3e1337-109256

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- Definition

Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

+ References

No definition available.

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