Benefit Plans - Summary of Company's Restricted Stock Units Activity (Detail) - Restricted Stock Units [Member] - 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]
Number of Shares, Beginning Balance	171,677	187,408	217,408
Number of Shares, granted	101,340	92,320	95,028
Number of Shares, vested	(90,070)	(86,402)	(114,274)
Number of Shares, cancelled/forfeited/expired	(1,913)	(21,649)	(10,754)
Number of Shares, Ending Balance	181,034	171,677	187,408
Weighted-Average Grant Date Fair Value, Beginning Balance	$ 92.18	$ 76.74	$ 67.63
Weighted-Average Grant Date Fair Value, granted	114.64	103.56	77.79
Weighted-Average Grant Date Fair Value, vested	85.14	50.98	58.30
Weighted-Average Grant Date Fair Value, cancelled/forfeited/expired	95.33	82.69	70.10
Weighted-Average Grant Date Fair Value, Ending Balance	$ 108.05	$ 92.18	$ 76.74
Aggregate Intrinsic Value	$ 20.2