Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Valuation and qualifying accounts
Balance at beginning of period	$ 193.5	$ 199.3	$ 198.3
Expense	104.9	72.0	86.1
Deferral	35.8	88.3	62.9
Net write-offs	(171.4)	(166.1)	(148.0)
Balance at end of period	$ 162.8	$ 193.5	$ 199.3