Reconciliation of Earnings per Share and Shares in Computation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income	$ 110,472	$ 87,240	$ 85,762
Earnings per share:
Basic	$ 1.74	$ 1.37	$ 1.33
Effect of CESs	(0.02)	(0.01)	(0.01)
Diluted	$ 1.72	$ 1.36	$ 1.32
Weighted average number of shares:
Basic	63,445	63,538	64,397
Effect of CESs	878	795	706
Diluted	64,323	64,333	65,103