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Organization and Description of Business - Additional Information (Detail) | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2018 USD ($) Segment | Apr. 17, 2018 USD ($) | Dec. 31, 2017 USD ($)
Schedule of Capitalization, Equity [Line Items] |  |  |
Number of reportable segments | Segment | 2 |  |
Accumulated deficit | $ 274,058,000 |  | $ 268,022,000
Cash and cash equivalents | 18,695,000 |  | 16,895,000
Debt outstanding under debt and capital lease obligations | 10,200,000 |  |
Current debt | $ 461,000 |  | $ 15,721,000
Subsequent Event [Member] | New Credit Agreement [Member] |  |  |
Schedule of Capitalization, Equity [Line Items] |  |  |
Aggregate principal amount |  | $ 15,000,000 |
Subsequent Event [Member] | New Credit Agreement [Member] | Tranche B Term Loan [Member] |  |  |
Schedule of Capitalization, Equity [Line Items] |  |  |
Aggregate principal amount |  | $ 10,000,000 |

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