Statements Of Consolidated Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Activities
Net Income	$ 211.3	$ 186.6
Adjustments to Reconcile Net Income to Net Cash from Continuing Operations:
Depreciation and amortization	143.3	132.8
Deferred income taxes and investment tax credits	109.4	95.1
Other adjustments	11.0	10.0
Changes in Assets and Liabilities:
Components of working capital	(117.5)	(37.9)
Regulatory assets/liabilities	69.3	(81.3)
Other noncurrent assets	(1.2)	0.2
Other noncurrent liabilities	(14.5)	(2.3)
Net Operating Activities from Continuing Operations	411.1	303.2
Net Operating Activities used for Discontinued Operations	0.0	(0.3)
Net Cash Flows from Operating Activities	411.1	302.9
Investing Activities
Capital expenditures	(312.0)	(301.0)
Cost of removal	(31.4)	(21.6)
Other investing activities	(0.8)	7.3
Net Cash Flows used for Investing Activities	(344.2)	(315.3)
Financing Activities
Repayments of long-term debt and capital lease obligations	(36.6)	(204.3)
Premiums and other debt related costs	0.0	(0.3)
Change in short-term borrowings, net	26.2	277.9
Issuance of common stock	6.4	4.3
Acquisition of treasury stock	(4.4)	(7.4)
Dividends paid - common stock	(56.5)	(49.6)
Net Cash Flows from (used for) Financing Activities	(64.9)	20.6
Change in cash and cash equivalents from continuing operations	2.0	8.5
Change in cash and cash equivalents from discontinued operations	0.0	(0.3)
Cash and cash equivalents at beginning of period	26.4	15.5
Cash and Cash Equivalents at End of Period	$ 28.4	$ 23.7