Convertible Senior Notes - Components of Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Liability component:
Net carrying amount	$ 109,772
Equity component	32,607
Convertible Debt
Liability component:
Convertible senior notes	143,750	$ 143,800
Less: debt discount, net of amortization	$ (33,978)

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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.

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- Definition

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

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Amount, after accumulated amortization, of debt discount.

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