Consolidated Income Statements (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Revenues	$ 4,519.0	$ 4,246.4	$ 4,486.4
Operating Expenses
Fuel and purchased power	1,153.0	1,098.6	1,169.7
Cost of gas sold	674.1	545.8	728.7
Other operation and maintenance	1,155.0	1,116.1	1,256.8
Depreciation and amortization	388.1	364.2	330.2
Property and revenue taxes	116.7	121.4	113.7
Total Operating Expenses	3,486.9	3,246.1	3,599.1
Revenue from Grants	48.0	0	0
Operating Income	1,080.1	1,000.3	887.3
Income (Loss) from Equity Method Investments	68.4	65.5	61.6
Other Income and Deductions, net	18.8	34.8	62.7
Interest Expense, net	252.1	248.2	235.8
Income (Loss) from Continuing Operations Before Income Taxes	915.3	852.6	776.7
Total Income Tax Expense, Amount	337.9	306.3	263.9
Income from Continuing Operations	577.4	546.3	512.8
Income from Discontinued Operations, Net of Tax	0	0	13.4
Net Income	577.4	546.3	526.2
Earnings Per Share (Basic)
Continuing Operations	$ 2.54	$ 2.37	$ 2.20
Discontinued Operations	$ 0.00	$ 0.00	$ 0.06
Total Earnings Per Share (Basic)	$ 2.54	$ 2.37	$ 2.26
Earnings Per Share (Diluted)
Continuing Operations	$ 2.51	$ 2.35	$ 2.18
Discontinued Operations	$ 0.00	$ 0.00	$ 0.06
Total Earnings Per Share (Diluted)	$ 2.51	$ 2.35	$ 2.24
Weighted Average Common Shares Outstanding (Millions)
Basic	227.6	230.2	232.6
Diluted	229.7	232.8	235.4
Transmission Affiliate [Member]
Operating Expenses
Income (Loss) from Equity Method Investments	$ 68.5	$ 65.7	$ 62.5