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	$ 137.9	$ 134.8	$ 125.9
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization expense	106.2	96.2	95.6
Recoveries and refunds of regulatory assets and liabilities	(13.2)	15.1	30.8
Bad debt expense	5.2	5.7	7.4
Pension and other postretirement expense	22.2	18.9	19.1
Pension and other postretirement contributions	(43.5)	(122.0)	(73.0)
Deferred income taxes and investment tax credit	79.4	33.4	53.6
Repayment of related party payables	0	(22.6)	(21.2)
Equity income, net of dividends	(1.8)	(1.5)	(1.4)
Termination of tolling agreement with Fox Energy Company LLC	(50.0)	0	0
Other	5.0	(3.7)	14.5
Changes in working capital
Collateral on deposit	1.2	(0.6)	0
Accounts receivable and accrued unbilled revenues	(24.8)	2.9	(2.3)
Inventories	18.9	11.9	(26.2)
Prepaid taxes	21.1	27.9	(22.7)
Other current assets	(1.7)	0.4	3.9
Accounts payable	(14.9)	3.0	(4.7)
Other current liabilities	25.9	23.5	(18.0)
Net cash provided by operating activities	273.1	223.3	181.3
Investing Activities
Capital expenditures	(241.6)	(179.5)	(91.5)
Proceeds from sale of property, plant, and equipment	1.9	3.1	2.7
Acquisition of Fox Energy Company LLC	(391.6)	0	0
Grant received related to Crane Creek Wind Project	69.0	0	0
Other	5.7	4.2	2.7
Net cash used for investing activities	(556.6)	(172.2)	(86.1)
Financing Activities
Short-term debt, net	(69.8)	(78.3)	173.7
Borrowing on term credit facility	200.0	0	0
Repayment of term credit facility	(200.0)	0	0
Repayment of notes payable	0	0	(10.0)
Repayment of long-term debt	(147.0)	(150.0)	(150.0)
Repayment of long-term debt to parent	(0.9)	(0.7)	(0.7)
Issuance of long-term debt	450.0	300.0	0
Payments of dividend to parent	(108.6)	(105.5)	(102.5)
Equity contribution from parent	200.0	40.0	20.0
Return of capital to parent	(35.0)	(50.0)	(89.3)
Preferred stock dividend requirements	(3.1)	(3.1)	(3.1)
Other	(2.9)	(2.5)	0.8
Net cash provided by (used for) financing activities	282.7	(50.1)	(161.1)
Net change in cash and cash equivalents	(0.8)	1.0	(65.9)
Cash and cash equivalents at beginning of year	6.5	5.5	71.4
Cash and cash equivalents at end of year	5.7	6.5	5.5
Supplemental Cash Flow Information
Cash paid for interest	43.9	40.2	49.2
Cash (received) paid for income taxes	$ (27.3)	$ 2.9	$ 38.0