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, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning Balance	217,408	225,970	196,248
Number of Shares, granted	95,028	116,326	126,540
Number of Shares, vested	(114,274)	(116,242)	(89,225)
Number of Shares, cancelled/forfeited/expired	(10,754)	(8,646)	(7,593)
Number of Shares, Ending Balance	187,408	217,408	225,970
Weighted-Average Grant Date Fair Value, Beginning Balance	$ 67.63	$ 57.06	$ 50.68
Weighted-Average Grant Date Fair Value, granted	77.79	72.75	50.99
Weighted-Average Grant Date Fair Value, vested	58.30	53.32	43.42
Weighted-Average Grant Date Fair Value, cancelled/forfeited/expired	70.10	52.78	57.93
Weighted-Average Grant Date Fair Value, Ending Balance	$ 76.74	$ 67.63	$ 57.06
Aggregate Intrinsic Value	$ 18.4