Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Common Stock	Retained earnings	AOCI	Non-controlling interests
Beginning balance (in shares) at Dec. 31, 2022		229,546,105
Beginning balance at Dec. 31, 2022	$ 9,493.3	$ 7,219.7	$ 2,298.5	$ (34.5)	$ 9.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	145.7		142.6		3.1
Issuance of stock compensation and reinvested dividends, net of tax withholding (in shares)		130,594
Issuance of stock, net issuance costs	(2.4)	$ (2.4)
Dividends declared on common stock	(140.7)		(140.7)
Dividend equivalents declared	(0.4)		(0.4)
Stock compensation expense	4.7	4.7
Unearned compensation
Compensation expense recognized	0.1	0.1
Derivative hedging activity, net of tax	1.3			1.3
Other	0.1	$ 0.1
Ending balance (in shares) at Mar. 31, 2023		229,676,699
Ending balance at Mar. 31, 2023	9,501.7	$ 7,222.2	2,300.0	(33.2)	12.7
Beginning balance (in shares) at Dec. 31, 2023		229,729,296
Beginning balance at Dec. 31, 2023	9,685.0	$ 7,234.9	2,457.8	(29.6)	21.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125.8		122.7		3.1
Issuance of stock compensation and reinvested dividends, net of tax withholding (in shares)		193,042
Issuance of stock, net issuance costs	(4.0)	$ (4.0)
Dividends declared on common stock	(147.7)		(147.7)
Dividend equivalents declared	(0.4)		(0.4)
Stock compensation expense	3.9	3.9
Unearned compensation
Derivative hedging activity, net of tax	1.3			1.3
Other	0.2	$ 0.2
Ending balance (in shares) at Mar. 31, 2024		229,922,338
Ending balance at Mar. 31, 2024	$ 9,664.1	$ 7,235.0	$ 2,432.4	$ (28.3)	$ 25.0