Summary of Nonvested Restricted Shares Activity (Detail) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
GRANT DATE FAIR VALUE
Nonvested awards outstanding, beginning balance | $ / shares	$ 59.69	[1]
Granted | $ / shares	71.27	[1]
Vested | $ / shares	63.06	[1]
Forfeited | $ / shares	60.25	[1]
Nonvested awards outstanding, ending balance | $ / shares	$ 66.21	[1]
NONVESTED NUMBER OF SHARES
Nonvested awards outstanding, beginning balance | shares	241,500
Granted | shares	197,000
Vested | shares	(168,700)
Forfeited | shares	(8,000)
Nonvested awards outstanding, ending balance | shares	261,800

[1] Weighted Average