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Common Stock and Warrants - Summary of Warrants Accounts for as Liabilities (Detail) - USD ($) | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
Fair Value Disclosures [Abstract] |  |
Fair value of warrants at beginning of period | $ 6,941 | $ 2,857
Exercise of warrants | (2,509) |
Change in fair value of warrants during the period | (1,954) | 354
Fair value of warrants at end of period | $ 2,478 | $ 3,211

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- Definition Fair value of warrants liability exercise. + References No definition available. + Details
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- Definition Amount of expense (income) related to adjustment to fair value of warrant liability. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section 25 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6939902&loc=d3e20148-110875 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
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