Consolidated Condensed Income Statements (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Operating Revenues	$ 1,043.7	$ 1,012.3	$ 2,738.7	$ 2,287.5
Operating Expenses
Fuel and purchased power	292.5	276.1	611.1	547.1
Cost of gas sold	125.9	115.2	717.4	385.3
Other operation and maintenance	256.0	265.4	531.4	553.5
Depreciation and amortization	101.4	96.7	202.0	192.2
Property and revenue taxes	30.3	29.4	60.9	58.9
Total Operating Expenses	806.1	782.8	2,122.8	1,737.0
Revenue from Grants	3.1	0	6.6	0
Operating Income	240.7	229.5	622.5	550.5
Income (Loss) from Equity Method Investments	17.5	17.2	34.8	33.9
Other Income, net	8.1	5.8	9.2	10.2
Interest Expense, net	59.0	63.3	121.3	128.3
Income from Continuing Operations Before Income Taxes	207.3	189.3	545.2	466.3
Income Tax Expense	74.3	70.3	204.6	170.7
Net Income	133.0	119.0	340.6	295.6
Earnings Per Share (Basic)
Continuing operations	$ 0.59	$ 0.52	$ 1.51	$ 1.29
Earnings Per Share (Diluted)
Continuing operations	$ 0.58	$ 0.52	$ 1.50	$ 1.28
Weighted Average Common Shares Outstanding (Millions)
Basic	225.5	228.4	225.6	228.6
Diluted	227.6	230.5	227.7	230.8
Dividends Per Share of Common Stock	$ 0.39	$ 0.34	$ 0.78	$ 0.68
Transmission Affiliate [Member]
Operating Expenses
Income (Loss) from Equity Method Investments	$ 17.5	$ 17.3	$ 34.8	$ 33.9