Reconciliation of Weighted Average Shares Outstanding - Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Basic (in shares)	182.3	183.5	182.5	183.4
Dilutive effect of shares issuable under stock-based compensation plans (in shares)	0.7	0.6	0.7	0.7
Diluted (in shares)	183.0	184.1	183.2	184.1
Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above (in shares)	0.4	0.4	0.4	0.5