Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Earnings Per Share [Abstract]
NET INCOME	$ 215.1	$ 86.4	$ 175.5	$ 185.8	$ 130.2	$ 190.1	$ 477.0	$ 506.1
Basic weighted average common shares outstanding (in shares)	37.6			39.9			38.2	40.8
Dilutive effect of unvested RSUs (in shares)	0.5			0.4			0.4	0.3
Diluted weighted average common shares outstanding (in shares)	38.1			40.3			38.6	41.1
Basic EPS (in dollars per share)	$ 5.72			$ 4.66			$ 12.49	$ 12.40
Diluted EPS (in dollars per share)	$ 5.65			$ 4.61			$ 12.36	$ 12.31