Convertible Senior Notes - Schedule of Components of Convertible Senior Notes (Details) - Convertible Senior Notes - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2017
Liability component:
Principal	$ 115,000	$ 115,000	$ 115,000
Less: debt discount, net of amortization	(20,903)	(25,519)
Net carrying amount	94,097	89,481
Equity component	$ 22,094	$ 22,094

Debt instrument unamortized discount.

No definition available.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

+ References

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-Publisher FASB
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- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

Amount, after accumulated amortization, of debt discount.

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