Property and Equipment - Additional Information (Detail) - USD ($) |
12 Months Ended | |
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Dec. 31, 2017 |
Dec. 31, 2016 |
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| Property Plant And Equipment [Abstract] | ||
| Depreciation | $ 155,000 | $ 65,000 |
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- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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