Convertible Notes, net - Schedule of Outstanding Convertible Note Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Liability component:
Net carrying amount of Convertible Notes as of March 31, 2018	$ 0	$ 258,538
Convertible Notes
Liability component:
Principal	324,998	324,998
Unamortized related debt discount	(37,968)	(66,460)
Net carrying amount of Convertible Notes as of March 31, 2018	$ 287,030	$ 258,538

Carrying Amounts Of Liability And Equity Components Of Convertible Debt [Abstract]

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- Definition

Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Convertible Notes Payable, excluding current portion. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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-Section 55
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- Definition

Amount, after accumulated amortization, of debt discount.

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-Publisher FASB
-Name Accounting Standards Codification
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