Basic Net Income (loss) Per Share is Calculated Using Weighted Average Number of Shares (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings per share – basic	$ 0.28	$ 0.22	$ 0.43	$ 0.48
Earnings per share – diluted	$ 0.24	$ 0.20	$ 0.37	$ 0.42
Weighted average shares of common stock outstanding – basic	32,917,007	25,067,954	32,672,793	25,067,954
Weighted average shares of common stock outstanding – diluted	38,387,700	28,417,877	38,010,838	28,417,877