Debt - Schedule of Interest Expense Recognized Related to Notes (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2019
Debt Disclosure [Abstract]
Contractual interest expense	$ 72	$ 72
Amortization of debt discount	897	897
Amortization of transaction costs	111	111
Total	$ 1,080	$ 1,080

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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No definition available.

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

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