Share-Based Compensation Plans - Outstanding Restricted Stock Unit Awards (Detail) - Restricted Stock Unit Awards - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
NUMBER
Balance at beginning of period (in shares)	2,715,437
Granted (in shares)	1,015,151
Distributed (in shares)	(979,218)
Forfeited (in shares)	(159,305)
Balance at end of period (in shares)	2,592,065
Units Convertible, at the end of year (in shares)	18,887
AGGREGATE INTRINSIC VALUE
AGGREGATE INTRINSIC VALUE	$ 354.1	$ 278.3
Units Convertible, at the end of year	$ 2.6