CONDENSED STATEMENTS OF INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
OPERATING REVENUES	$ 455.5	$ 426.7
COST OF GOODS SOLD (exclusive of depreciation and amortization shown below)	213.0	195.5
Gross margin on revenues	242.5	231.2
OPERATING EXPENSES
Other operation and maintenance	105.1	110.6
Depreciation and amortization	61.3	59.7
Taxes other than income	23.2	21.1
Total operating expenses	189.6	191.4
OPERATING INCOME	52.9	39.8
OTHER INCOME (EXPENSE)
Interest income	0.1	0
Allowance for equity funds used during construction	1.2	1.9
Other income	2.6	5.2
Other expense	(0.5)	(0.7)
Net other income	3.4	6.4
INTEREST EXPENSE
Interest on long-term debt	31.1	31.0
Allowance for borrowed funds used during construction	(0.7)	(1.1)
Interest on short-term debt and other interest charges	1.0	1.0
Interest expense	31.4	30.9
INCOME BEFORE TAXES	24.9	15.3
INCOME TAX EXPENSE	11.9	3.2
NET INCOME	$ 13.0	$ 12.1