Earnings per Share - Computation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income	$ 28,222	$ 27,422	$ 28,362	$ 33,649	$ 23,657	$ 17,606	$ 7,430	$ 16,121	$ 117,655	$ 64,814	$ 92,072
Average number of common shares outstanding (in shares)									29,721	29,917	30,478
Effect of dilutive stock options and restricted stock (in shares)									161	111	167
Average number of common shares outstanding used to calculate diluted earnings per share (in shares)									29,882	30,028	30,645
Options excluded from diluted earnings per share because the effect of these options was antidilutive (in shares)									0	0	0