Debt - Summary of Carrying Amount of Term Loan (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Short And Long Term Debt [Line Items]
Beginning balance	$ (136)
Accretion of debt discount	27
Accretion of issuance costs, debt discount	0
Ending balance	(109)
Beginning balance	(15)
Accretion of issuance costs, issuance costs	4
Ending balance	(11)
Beginning balance	5,803
Accretion of debt discount	27
Accretion of issuance costs	4
Principal payments	(651)
Ending balance	5,183
Current portion of debt, net of debt discount and issuance costs	2,661	$ 2,586
Long term portion of debt, net of current portion	2,522	$ 3,217
Hercules Term Loan [Member]
Short And Long Term Debt [Line Items]
Beginning balance	5,954
Accretion of issuance costs, term loan	0
Principal payments	(651)
Ending balance	$ 5,303

Amortization of Financing Costs, Term Loan

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- Definition

Debt instrument accretion of debt discount.

+ References

No definition available.

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- Definition

Short And Long Term Debt [Line Items]

+ References

No definition available.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
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- Definition

Amount of amortization expense attributable to debt issuance costs.

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- Definition

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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-Name Accounting Standards Codification
-Topic 230
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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/presentationRef
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- Definition

Amount of the required periodic payments applied to principal.

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- Definition

Amount, after accumulated amortization, of debt discount.

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- 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.

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

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