CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 602.5	$ 997.3	$ 532.4
Other comprehensive (loss) income:
Change in fair value of cash flow swaps	(22.6)	103.3	6.3
Unrealized gains (losses) on available-for-sale debt securities	5.2	(4.0)	0.2
Income tax benefit (expense) associated with other comprehensive income items	4.0	(24.3)	(1.6)
Comprehensive income	$ 589.1	$ 1,072.2	$ 537.3