Stock-Based Compensation - Summary of Activity in Corporation's Active Stock Plans (Detail)	3 Months Ended
	Mar. 31, 2026 $ / shares shares
Deferred Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Number of Shares/Units | shares	61,539
Ending Balance, Number of Shares/Units | shares	61,539
Beginning Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 98.38
Ending Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 98.38
Non-Vested Restricted Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Number of Shares/Units | shares	586,298
Granted, Number of Units | shares	183
Stock Awards exercised/vested, Number of Shares | shares	(2,114)
Forfeited/expired, Number of Shares/Units | shares	(3,061)
Ending Balance, Number of Shares/Units | shares	581,306
Beginning Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 111.39
Granted Weighted-Average Grant-Date Fair Value | $ / shares	136.33
Stock Award Exercised/Vested, Weighted Average Grant Date Fair Value | $ / shares	127.77
Forfeited/Expired, Weighted-Average Price | $ / shares	111.73
Ending Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 111.52
Maximum [Member] | Performance Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Number of Shares/Units | shares	219,512
Stock Awards exercised/vested, Number of Shares | shares	(26,844)
Forfeited/expired, Number of Shares/Units | shares	(25,683)
Ending Balance, Number of Shares/Units | shares	166,985
Beginning Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 101.23
Stock Award Exercised/Vested, Weighted Average Grant Date Fair Value | $ / shares	130.26
Forfeited/Expired, Weighted-Average Price | $ / shares	130.26
Ending Balance, Weighted-Average Grant-Date Fair Value | $ / shares	$ 91.11