Stock Based Compensation - Summary of Stock Option and Stock Appreciation Rights ("SARs") Restricted Stock Units ("RSUs") and Performance Stock Units ("PSU") Activity (Detail) shares in Millions	3 Months Ended
	Mar. 31, 2024 shares
Stock Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding Opening	38.8
Cancelled/forfeited	(0.5)
Exercised	(1.3)
Vested	0.0
Number of Shares, Outstanding Closing	38.8
Granted	1.8
PSUs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding Opening	3.5
Granted	3.4
Cancelled/forfeited	(0.8)
Exercised	0.0
Vested	(0.3)
Number of Shares, Outstanding Closing	5.8