CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities
Net income	$ 120.2	$ 159.6
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization expense	149.9	147.9
Deferred income taxes and investment tax credits, net	58.3	83.4
Pension and other postretirement contributions	(6.2)	(69.5)
Goodwill impairment loss	0.0	6.7
Impairment loss on property, plant, and equipment at PDL	10.7	0.0
Gain on sale of certain PDL solar power generation plants	(6.1)	0.0
Changes in working capital
Accounts receivable and accrued unbilled revenues	274.2	136.1
Inventories	97.4	30.9
Other current assets	26.4	96.3
Accounts payable	(67.5)	(15.8)
Other current liabilities	47.0	0.3
Other, net	(30.7)	15.2
Net cash provided by operating activities	673.6	591.1
Investing Activities
Capital expenditures	(424.5)	(337.9)
Investment in transmission affiliate	(3.4)	(10.2)
Cost of removal, net of salvage	(7.0)	(6.4)
Rabbi trust funding related to change in control	(14.3)	(65.0)
Withdrawal of restricted cash from Rabbi trust for qualifying payments	14.1	0.0
Proceeds from sale of certain PDL solar power generation plants	47.6	0.0
Purchase of natural gas distribution business in Minnesota	(11.0)	0.0
Other, net	2.8	(10.3)
Net cash used for investing activities	(395.7)	(429.8)
Financing Activities
Exercise of stock options	4.1	11.9
Purchase of common stock	(23.9)	(29.3)
Dividends paid on common stock	(108.2)	(108.2)
Retirement of long-term debt	0.0	(100.0)
Change in short-term debt	(3.2)	94.7
Other, net	(8.4)	(7.7)
Net cash used for financing activities	(139.6)	(138.6)
Net change in cash and cash equivalents	138.3	22.7
Cash and cash equivalents at beginning of period	18.0	22.3
Cash and cash equivalents at end of period	156.3	45.0
Supplemental Cash Flow Information
Cash paid for interest	74.9	74.5
Cash received for income taxes	$ (45.4)	$ (59.2)