CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating revenues	$ 1,563.1	$ 1,589.0	$ 1,583.8
Cost of fuel, natural gas, and purchased power	731.9	722.5	767.8
Operating and maintenance expense	452.2	455.0	424.2
Restructuring expense	0.2	(0.3)	10.4
Depreciation and amortization expense	95.6	110.6	107.1
Taxes other than income taxes	47.8	46.2	48.7
Operating income	235.4	255.0	225.6
Miscellaneous income	13.2	12.4	16.8
Interest expense	(49.5)	(54.4)	(54.0)
Other expense	(36.3)	(42.0)	(37.2)
Income before taxes	199.1	213.0	188.4
Provision for income taxes	73.2	78.0	68.0
Net income	125.9	135.0	120.4
Preferred stock dividend requirements	(3.1)	(3.1)	(3.1)
Net income attributed to common shareholder	$ 122.8	$ 131.9	$ 117.3