Earnings per Share - Number of Shares Outstanding for Calculation of Earnings Per Share (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator (for basic and diluted earnings (loss) per share)
Net (loss) income	$ (239)	$ 1,931	$ 6,431	$ 9,310
Denominator
Basic weighted-average shares outstanding	35,358,913	35,070,449	35,263,688	34,944,056
Common stock equivalents arising from stock options and restricted stock awards		555,000	208,000	579,000
Diluted weighted-average shares outstanding	35,358,913	35,624,590	35,471,551	35,522,568