Reconciliation of Earnings per Share and Shares in Computation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net income	$ 29,674	$ 36,654	$ 91,091	$ 89,890
Earnings per share:
Basic	$ 0.47	$ 0.58	$ 1.45	$ 1.42
Effect of CESs		(0.01)	(0.02)	(0.02)
Diluted	$ 0.47	$ 0.57	$ 1.43	$ 1.40
Weighted average number of shares:
Basic	62,592	63,363	62,917	63,514
Effect of CESs	573	875	566	825
Diluted	63,165	64,238	63,483	64,339