Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Allowance for credit losses	$ 18,500,000	$ 24,200,000
Regulatory assets	330,100,000	292,100,000
PROPERTY, PLANT AND EQUIPMENT, NET, includes $131.8 and $133.6 related to variable interest entity, respectively	23,945,700,000	23,728,700,000
Current maturities of long-term debt	811,500,000	800,000,000.0
Long-term debt, net	$ 11,658,400,000	$ 11,053,300,000
Common stock - shares authorized (in shares)	600,000,000	600,000,000
Common stock - shares issued (in shares)	229,922,338	229,729,296
Variable Interest Entities
Regulatory assets	$ 15,200,000	$ 0
PROPERTY, PLANT AND EQUIPMENT, NET, includes $131.8 and $133.6 related to variable interest entity, respectively	131,800,000	133,600,000
Current maturities of long-term debt	11,500,000	0
Long-term debt, net	$ 311,500,000	$ 0