CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Other Comprehensive Income [Abstract]
Net income	$ 622.6	$ 507.6
Derivatives accounted for as cash flow hedges
Reclassification of realized derivative gains to net income, net of tax	(0.1)	(0.1)
Comprehensive income	622.5	507.5
Preferred stock dividends of subsidiary	0.3	0.3
Comprehensive loss attributed to noncontrolling interests	0.0	0.2
Comprehensive income attributed to common shareholders	$ 622.2	$ 507.4