Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Activities
Net income	$ 577.4	$ 546.3	$ 526.2
Reconciliation to cash
Depreciation and amortization	400.2	371.7	336.4
Deferred income taxes and investment tax credits, net	312.7	293.2	430.6
Contributions to qualified benefit plans	0	(100.0)	(277.4)
Change in -
Accounts receivable and accrued revenues	(162.9)	38.3	30.1
Inventories	31.3	21.3	(2.9)
Other current assets	2.8	12.1	(20.5)
Accounts payable	(14.8)	43.8	11.8
Accrued income taxes, net	36.6	116.9	(87.4)
Deferred costs, net	(8.7)	9.2	25.9
Other current liabilities	7.2	(14.9)	44.1
Other, net	49.2	(164.0)	(23.5)
Cash Provided by Operating Activities	1,231.0	1,173.9	993.4
Investing Activities
Capital expenditures	(687.4)	(707.0)	(830.8)
Investment in transmission affiliate	(10.5)	(15.7)	(6.6)
Proceeds from asset sales	2.5	8.7	41.5
Change in restricted cash	2.7	42.8	(37.2)
Payments for (Proceeds from) Removal Costs	(37.8)	(38.3)	(16.9)
Other, net	(15.3)	(20.1)	(42.5)
Cash Used in Investing Activities	(745.8)	(729.6)	(892.5)
Financing Activities
Exercise of stock options	48.5	49.8	54.4
Purchase of common stock	(223.4)	(153.2)	(193.9)
Dividends paid on common stock	(328.9)	(276.3)	(242.0)
Issuance of long-term debt	251.0	251.8	720.0
Retirement and repurchase of long-term debt	(397.2)	(20.3)	(466.6)
Change in short-term debt	142.8	(275.3)	12.0
Other, net	12.4	0.7	4.8
Cash Used in Financing Activities	(494.8)	(422.8)	(111.3)
Change in Cash and Cash Equivalents	(9.6)	21.5	(10.4)
Cash and Cash Equivalents at Beginning of Year	35.6	14.1	24.5
Cash and Cash Equivalents at End of Year	$ 26.0	$ 35.6	$ 14.1