Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Outstanding Warrants Valuation Assumption (Detail)

v3.8.0.1
Stockholders' Equity - Outstanding Warrants Valuation Assumption (Detail) - $ / shares
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Fair Value Disclosures [Abstract]    
Risk-free interest rate 2.27% 1.89%
Expected life (in years) 1 year 10 months 20 days 2 years 1 month 17 days
Dividend yield 0.00% 0.00%
Volatility 89.00% 103.00%
Stock price $ 8.00 $ 10.02