Notes Payable - Schedule of Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument
Total notes payable	$ 42,268	$ 41,704
Less: current portion of notes payable	(3,399)	(40,696)
Notes payable, net of current portion	38,869	1,008
Medium-term Notes [Member] \| Term Loan Agreement [Member]
Debt Instrument
Total notes payable	40,869	39,228
Line of Credit [Member] \| Equipment Lease Credit Facility [Member]
Debt Instrument
Total notes payable	$ 1,399	$ 2,476

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.

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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- Definition

Sum of the carrying values as of the balance sheet date of the portions of long-term notes payable due within one year or the operating cycle if longer.

+ References

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