CAPITAL STOCK - Schedule of Common Shares Purchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Aggregate cost (including transaction fees) of common shares repurchased for cancellation	$ 75.0	$ 16.5
Number of common shares repurchased for cancellation (in shares)	0.6	0.5
Weighted average price per share for repurchases (in dollars per share)	$ 114.46	$ 35.96
Aggregate cost (including transaction fees) of Common Shares repurchased for delivery under SBC plans	$ 221.6	$ 101.6
Treasury stock, shares, acquired for share-based compensation plans (in shares)	1.7	2.8
NCIB ASPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of common shares repurchased for cancellation (in shares)		0.5