Stock Compensation - Summary of Warrant Activity (Detail) - Warrant - $ / shares |
12 Months Ended | |
---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Number of shares, outstanding | 450,000 | 650,000 |
Number of shares, granted | 0 | 0 |
Number of shares, exercised | (450,000) | (200,000) |
Number of shares, expired/cancelled | 0 | 0 |
Number of shares, outstanding | 0 | 450,000 |
Weighted average exercise price, outstanding (in dollars per share) | $ 1.50 | $ 1.48 |
Weighted average exercise price, granted (in dollars per share) | 0 | 0 |
Weighted average exercise price, exercised (in dollars per share) | 1.50 | 0 |
Weighted average exercise price, exercised/cancelled (in dollars per share) | 0 | 0 |
Weighted average exercise price, outstanding (in dollars per share) | $ 0 | $ 1.50 |