Equity Compensation Plans - Summary of Restricted Share Units Activity, Performance Share Activity and Restricted Stock Activity (Detail)	12 Months Ended
	Dec. 31, 2025 $ / shares shares
Restricted Share Units
Shares
Nonvested, beginning balance (in shares) | shares	99,018
Granted (in shares) | shares	41,250
Vested (in shares) | shares	(42,158)
Forfeited (in shares) | shares	(3,411)
Achievement level adjustment (in shares) | shares	0
Shares settled for cash (in shares) | shares	(3,494)
Nonvested, ending balance (in shares) | shares	91,205
Weighted- Average Grant Date Fair Value
Nonvested, beginning balance (in dollars per share) | $ / shares	$ 138.75
Granted (in dollars per share) | $ / shares	189.13
Vested (in dollars per share) | $ / shares	127.63
Forfeited (in dollars per share) | $ / shares	161.00
Achievement level adjustment (in dollars per share) | $ / shares	0
Shares settled for cash (in dollars per share) | $ / shares	127.08
Nonvested, ending balance (in dollars per share) | $ / shares	$ 165.22
Performance Shares
Shares
Nonvested, beginning balance (in shares) | shares	101,782
Granted (in shares) | shares	45,676
Vested (in shares) | shares	(40,580)
Forfeited (in shares) | shares	(2,510)
Achievement level adjustment (in shares) | shares	(15,174)
Shares settled for cash (in shares) | shares	0
Nonvested, ending balance (in shares) | shares	89,194
Weighted- Average Grant Date Fair Value
Nonvested, beginning balance (in dollars per share) | $ / shares	$ 187.91
Granted (in dollars per share) | $ / shares	264.11
Vested (in dollars per share) | $ / shares	148.97
Forfeited (in dollars per share) | $ / shares	200.44
Achievement level adjustment (in dollars per share) | $ / shares	148.97
Shares settled for cash (in dollars per share) | $ / shares	0
Nonvested, ending balance (in dollars per share) | $ / shares	$ 248.90