CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenues	$ 371.9	$ 378.1	$ 1,173.1	$ 1,119.8
Cost of fuel, natural gas, and purchased power	151.3	175.0	528.2	517.4
Operating and maintenance expense	115.9	103.0	340.1	316.3
Depreciation and amortization expense	27.6	24.1	78.8	72.0
Taxes other than income taxes	11.9	11.7	36.5	36.0
Operating income	65.2	64.3	189.5	178.1
Miscellaneous income	6.0	3.8	16.9	11.4
Interest expense	10.7	10.5	31.9	31.9
Other expense	(4.7)	(6.7)	(15.0)	(20.5)
Income before taxes	60.5	57.6	174.5	157.6
Provision for income taxes	22.8	14.4	64.7	48.1
Net income	37.7	43.2	109.8	109.5
Preferred stock dividend requirements	(0.7)	(0.7)	(2.3)	(2.3)
Net income attributed to common shareholder	$ 37.0	$ 42.5	$ 107.5	$ 107.2