Earnings/(loss) per share - Basic and Diluted Earnings Per Share Calculation (Detail) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (12,276,520)	$ (1,218,237)	$ (7,798,300)
Less: Undistributed earnings allocated to non-vested shares	0	0	0
Net loss attributable to common shareholders, basic	$ (12,276,520)	$ (1,218,237)	$ (7,798,300)
Weighted average number of shares outstanding, basic and diluted	39,860,563	39,809,364	39,824,038
Loss per share, basic and diluted	$ (0.31)	$ (0.03)	$ (0.20)

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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Amount of undistributed earnings (loss) allocated to participating securities for the diluted earnings (loss) per share or per unit calculation under the two-class method.

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- Definition

Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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No definition available.

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