Share-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance	788,495
Number of Shares, Granted	995	765
Number of shares withheld	14,000	20,000	22,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 6.1
SICP Awards to Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to the awards to Non employee directors	$ 0.3
Weighted average grant-date fair value of awards granted	$ 110.53	$ 124.12
SICP Awards to Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 103.95	$ 91.59
Number of Shares, Granted	110,000	81,000
Weighted average grant-date fair value of awards granted	$ 105.21	$ 126.06
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	$ 30.8	$ 22.5	$ 24.1
Stock and Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance	524,579