Consolidated Condensed Income Statements (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Revenues	$ 1,695.0	$ 1,275.2
Operating Expenses
Fuel and purchased power	318.6	271.0
Cost of gas sold	591.5	270.1
Other operation and maintenance	275.4	288.1
Depreciation and amortization	100.6	95.5
Property and revenue taxes	30.6	29.5
Total Operating Expenses	1,316.7	954.2
Revenue from Grants	3.5	0
Operating Income	381.8	321.0
Income (Loss) from Equity Method Investments	17.3	16.7
Other Income, net	1.1	4.4
Interest Expense, net	62.3	65.0
Income from Continuing Operations Before Income Taxes	337.9	277.0
Income Tax Expense	130.3	100.4
Net Income	207.6	176.6
Earnings Per Share (Basic)
Continuing operations	$ 0.92	$ 0.77
Earnings Per Share (Diluted)
Continuing operations	$ 0.91	$ 0.76
Weighted Average Common Shares Outstanding (Millions)
Basic	225.8	228.9
Diluted	227.7	231.2
Dividends Per Share of Common Stock	$ 0.39	$ 0.34
Transmission Affiliate [Member]
Operating Expenses
Income (Loss) from Equity Method Investments	$ 17.3	$ 16.6