CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating revenues
Regulated and Unregulated Operating Revenue	$ 5,111.8	$ 5,121.9	$ 5,102.0
Operating expenses
Cost of natural Gas Sold and Transported	327.2	345.1	301.8
Cost of sales — other	23.2	19.7	18.1
Operating and maintenance expenses	1,203.1	1,223.3	1,198.3
Conservation program expenses	119.7	118.0	120.1
Depreciation and amortization	791.3	741.6	700.6
Taxes (other than income taxes)	260.1	256.6	253.5
Total operating expenses	4,324.9	4,405.4	4,219.3
Operating income	786.9	716.5	882.7
Interest charges and financing costs
Interest charges — includes other financing costs of $7.4, $7.4 and $7.3 respectively	233.3	226.8	228.4
Public Utilities, Allowance For Funds Used During Construction, Capitalized Cost Of Debt	(12.4)	(12.5)	(15.1)
Total interest charges and financing costs	220.9	214.3	213.3
Other income, net	(0.8)	(6.5)	(9.1)
Allowance for funds used during construction — equity	24.8	23.8	29.5
Income before income taxes	590.0	519.5	689.8
Income taxes	47.4	27.2	199.7
Net income	542.6	492.3	490.1
Electricity, US Regulated
Operating expenses
Cost of Goods and Services Sold	1,600.3	1,701.1	1,626.9
Natural Gas, US Regulated
Operating revenues
Total operating revenues	571.3	583.1	531.9
Product and Service, Other [Member]
Operating revenues
Total operating revenues	33.9	30.8	28.4
Related Party Transaction, Electric Domestic Regulated Revenue [Member]
Operating revenues
Total operating revenues	457.4	473.7	490.2
Non-Related Party Transaction, Electric Domestic Regulated Revenue [Member] | Electricity, US Regulated
Operating revenues
Total operating revenues	$ 4,049.2	$ 4,034.3	$ 4,051.5