Convertible Notes - Summary of Issuance of Convertible Debt (Details) - Convertible Debt - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 21, 2016
Debt Instrument [Line Items]
Gross proceeds	$ 107,000	$ 107,000
Unamortized debt discounts and deferred financing offering costs	(11,946)	(13,488)
Net carrying amount	95,054	93,512	$ 81,580
Related Party
Debt Instrument [Line Items]
Gross proceeds	10,000	10,000
Unamortized debt discounts and deferred financing offering costs	(1,006)	(1,136)
Net carrying amount	8,994	8,864
Others
Debt Instrument [Line Items]
Gross proceeds	97,000	97,000
Unamortized debt discounts and deferred financing offering costs	(10,940)	(12,352)
Net carrying amount	$ 86,060	$ 84,648

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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-Name Accounting Standards Codification
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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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