Debt - Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt
Net carrying value of debt, Current Portion	$ 5,972	$ 5,977
Net carrying value of debt, Long-term debt	5,075	6,509
2017 Credit Facility
Debt
Debt, Current Portion	6,000	6,000
Less: Debt issuance costs, Current Portion	(28)	(33)
Net carrying value of debt, Current Portion	5,972	5,967
Debt, including end of term fee, Long-term debt	5,340	6,840
Less: Unamortized debt discounts, Long-term debt	(265)	(341)
Net carrying value of debt, Long-term debt	5,075	6,499
Total principal repayments	11,340	12,840
Less: Discount attributable to warrants, end of term fee and debt issuance costs, Total	(293)	(374)
Net carrying value of debt, Total	$ 11,047	$ 12,466

Long-term debt before unamortized (discount) premium, current.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Long-term debt before unamortized (discount) premium, noncurrent.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
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+ Details

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Balance Type:	credit
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- Definition

Amount, after accumulated amortization, of debt discount.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Amount of debt discount to be amortized within one year or within the normal operating cycle, if longer.

+ References

+ Details

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- Definition

Amount of debt discount to be amortized after one year or the normal operating cycle, if longer.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

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Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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