Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 59,690	$ 48,866	$ 41,899
Basic weighted average shares of Common Stock outstanding	32,666,025	33,120,076	35,920,782
Dilutive effect of stock options, restricted stock awards and restricted stock units	362,079	177,513	256,362
Diluted weighted average shares of Common Stock outstanding	33,028,104	33,297,589	36,177,144
Basic earnings per share	$ 1.83	$ 1.48	$ 1.17
Diluted earnings per share	$ 1.81	$ 1.47	$ 1.16
Anti-dilutive securities share impact	12,000	214,000	898,250