Computation of Earnings Per Share - Summary of Calculation of Basic Earnings Per Common Share and Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Numerator:
Net income	$ 362,065	$ 354,857	$ 357,422
Denominator:
Denominator for basic earnings per share–weighted average common shares	26,689	26,632	26,520
Dilutive effect of share-based awards	113	131	154
Denominator for diluted earnings per share–adjusted weighted average common shares	26,802	26,763	26,674
Basic Earnings Per Share	$ 13.57	$ 13.32	$ 13.48
Diluted Earnings Per Share	$ 13.51	$ 13.26	$ 13.40