Marketable Securities and Fair Value Measurements - Additional Information (Detail) - USD ($) |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
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| Schedule Of Available For Sale Securities [Line Items] | |||
| Realized gain or losses | $ 0 | $ 0 | |
| Shares of common stock to be purchased with warrants | 3,521,735 | 3,331,735 | |
| Long-term debt, carrying value | $ 3,000,000 | $ 3,500,000 | |
| 2017 Warrants | |||
| Schedule Of Available For Sale Securities [Line Items] | |||
| Shares of common stock to be purchased with warrants | 377,273 | 377,273 | |
| X | ||||||||||
- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Number of warrants or rights outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- 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. No definition available.
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| X | ||||||||||
- Details
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