Organization and Business - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands | Feb. 08, 2018 | Nov. 03, 2017 | May 21, 2017 | Jun. 30, 2016 | Jun. 30, 2015 | Mar. 31, 2018 | Dec. 31, 2017 | Jun. 13, 2017 | Mar. 31, 2017 | Dec. 31, 2016 |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Cash | | | | | | $ 4,284 | $ 5,965 | | $ 7,111 | $ 9,375 |
Stock issued during period, shares, new issues | | | | 588,235 | | | | | | |
Proceeds from issuance initial public offering | | | | $ 9,300 | | | | | | |
Proceeds from Warrant Exercises | | | $ 1,500 | | | | | | | |
Class of Warrant or Right, Exercisable, Number | | | 441,176 | | | | | | | |
Class of Warrant or Right, Exercised, Number | | | 11,176 | | | | | | | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings | | | | | | 400 | | | | |
Gain (Loss) on Extinguishment of Debt | | | | | | 400 | | | | |
Reclassified to equity | | | | | | 200 | | | | |
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings | | | | | | $ 1,000 | | | | |
Stockholders' Equity, Reverse Stock Split | 1-for-10 | | | | | | | | | |
Reduced Exercise Price [Member] | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Class of Warrant or Right, Exercised, Number | | | 430,000 | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | | | $ 3.80 | | | | | | | |
New Warrants [Member] | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | | | $ 6 | | | | | | | |
Class of Warrant or Right, Terms | | | 5 years | | | | | | | |
Warrants 2016 [Member] | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | 127,941 | | |
Warrant | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Stock issued during period, shares, new issues | | | | 294,118 | | | | | | |
Stock issued during period, value, new issues | | | | $ 10,000 | $ 25,000 | | | | | |
Proceeds from issuance initial public offering | | $ 3,600 | | | | | | | | |
2016 Registered Direct Offering | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Debt Issuance Costs, Net | | | | $ 300 | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | 25,000 | | | | | | |
2017 Registered Direct Offering | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Stock issued during period, shares, new issues | | 1,333,333 | | | | | | | | |
Stock issued during period, value, new issues | | $ 4,000 | | | | | | | | |
2017 Registered Direct Offering | Warrant | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Stock issued during period, shares, new issues | | 666,667 | | | | | | | | |
Roth Capital Partners, Llc [Member] | 2017 Registered Direct Offering | Warrant | | | | | | | | | | |
Organization and Nature of Operations [Line Items] | | | | | | | | | | |
Stock issued during period, shares, new issues | | 16,000 | | | | | | | | |