Debt - Net Carrying Amount of Liability Component of Debt Discount (Details) - Convertible Notes Payable - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Face amount of the Notes	$ 216,341,000	$ 213,959,000
Less unamortized discounts and debt issuance costs	(25,994,000)	(27,589,000)
Total net carrying value, current	190,347,000	186,370,000
Revolving Credit Facility
Debt Instrument [Line Items]
Face amount of the Notes	25,000,000	25,000,000
Senior Notes, due May 2023
Debt Instrument [Line Items]
Face amount of the Notes	66,090,000	66,090,000
Series B Senior Unsecured Convertible Notes
Debt Instrument [Line Items]
Face amount of the Notes	34,405,000	34,405,000
Senior Notes, due February 2023
Debt Instrument [Line Items]
Face amount of the Notes	$ 90,846,000	$ 88,464,000

Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

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