Percentage increase in interest applied to the outstanding debt balance in the event of default.

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Contractual interest rate base for funds borrowed under the debt agreement.

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Premium rate owed to lender for prepayments of any borrowings under the debt agreement.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount of the fee that accompanies borrowing money under the debt instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt discount (premium).

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

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

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Fair value of the amount outstanding under the credit facility.

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Increase for accrued, but unpaid interest on the credit facility for the period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Carrying value as of the balance sheet date of all notes and loans payable (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

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Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

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Debt (Details) - USD ($) $ in Thousands				3 Months Ended		9 Months Ended		12 Months Ended	43 Months Ended
Debt (Details) - USD ($) $ in Thousands	Apr. 30, 2019	Dec. 31, 2018	Aug. 08, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017	Mar. 31, 2019	Aug. 31, 2017	Sep. 30, 2015
Debt Instrument [Line Items]
Interest paid						$ 6,500	$ 6,100
Issuance of common stock to Orbimed						$ 506		$ 2,700
Common stock, shares issued		62,083,000		70,850,000		70,850,000
Amortization of debt discount				$ 100	$ 100	$ 336	293
Debt discount				900		900
Interest expense				2,672	2,781	8,117	7,730
Net carrying amount		$ 73,357		73,583		73,583
Line Of Credit-UBS
Debt Instrument [Line Items]
Maximum borrowing capacity											$ 50,000
Outstanding balance				50,100		50,100
Accrued interest									$ 1,100
Interest expense				400	400	$ 1,300	1,100
Line Of Credit-UBS \| 30-day LIBOR
Debt Instrument [Line Items]
Spread on interest rate (as a percent)						1.10%
2017 Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 100,000
Available borrowing capacity			75,000
Remaining borrowing capacity		$ 50,000	$ 25,000							$ 50,000
Interest expense				2,100	$ 2,100	$ 6,500	$ 6,100
Additional interest in the event of default (as a percent)			3.00%
Debt instrument, term			84 months
Common stock, shares issued	25,000									300,000
Debt instrument, fee amount				3,200		3,200
2017 Term Loan \| Minimum
Debt Instrument [Line Items]
Prepayment premium (as a percent)			2.50%
2017 Term Loan \| Maximum
Debt Instrument [Line Items]
Prepayment premium (as a percent)			12.50%
2017 Term Loan \| Base Rate
Debt Instrument [Line Items]
Spread on interest rate (as a percent)		8.50%	8.75%
Base interest rate (as a percent)		1.00%	1.00%
2017 Term Loan \| Base Rate \| Scenario of minimum capacity of $25.0 million drawn
Debt Instrument [Line Items]
Spread on interest rate (as a percent)	8.25%
2017 Term Loan \| Direct reduction from outstanding debt balance
Debt Instrument [Line Items]
Debt instrument, fee amount			$ 2,000
Unamortized debt discount				1,400		1,400
2017 Term Loan \| Noncurrent assets
Debt Instrument [Line Items]
Debt instrument, fee amount				$ 1,200		$ 1,200				$ 1,200