CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING REVENUES
Gas utility	$ 812.7	$ 771.7	$ 792.6
Electric utility	569.6	605.8	601.6
Nonutility	1,275.0	1,070.8	1,040.5
Total operating revenues	2,657.3	2,448.3	2,434.7
OPERATING EXPENSES
Cost of gas sold	271.5	266.7	305.4
Cost of fuel & purchased power	171.8	183.6	187.5
Cost of nonutility revenues	444.2	363.4	355.0
Other operating	1,115.9	932.2	909.2
Depreciation & amortization	276.2	260.0	256.3
Taxes other than income taxes	59.3	60.9	59.5
Total operating expenses	2,338.9	2,066.8	2,072.9
OPERATING INCOME	318.4	381.5	361.8
OTHER INCOME
Equity in earnings (losses) of unconsolidated affiliates	(1.1)	(0.2)	(0.6)
Other income – net	32.8	28.7	20.3
Total other income	31.7	28.5	19.7
Interest expense	87.7	85.5	84.5
INCOME BEFORE INCOME TAXES	262.4	324.5	297.0
Income taxes	46.4	112.9	99.7
NET INCOME	$ 216.0	$ 211.6	$ 197.3
WEIGHTED AVERAGE AND DILUTED COMMON SHARES OUTSTANDING	83.0	82.8	82.7
BASIC AND DILUTED EARNINGS PER SHARE OF COMMON STOCK (in dollars per share)	$ 2.60	$ 2.55	$ 2.39