Operations and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Operations and Significant Accounting Policies [Abstract]

Supplemental Statement of Cash Flow Information [Table Text Block]

Supplemental Statement of Cash Flow Information

Consolidated Statement of Cash Flows
Year Ended December 31	2014		2013		2012
Millions
Cash Paid During the Period for Interest – Net of Amounts Capitalized		$51.3		$47.5		$42.7
Cash Paid During the Period for Income Taxes		$5.1		$0.5	—
Noncash Investing and Financing Activities
Increase in Accounts Payable for Capital Additions to Property, Plant and Equipment		$21.7		$8.3	$20.2
Capitalized Asset Retirement Costs		$22.4	$(0.7)			$17.1
AFUDC – Equity		$7.8		$4.6		$5.1
ALLETE Common Stock Contributed to the Defined Benefit Pension Plan		$19.5	—		—

Accounts Receivable [Table Text Block]

Accounts Receivable. Accounts receivable are reported on the balance sheet net of an allowance for doubtful accounts. The allowance is based on our evaluation of the receivable portfolio under current conditions, overall portfolio quality, review of specific problems and such other factors that, in our judgment, deserve recognition in estimating losses.

Accounts Receivable
As of December 31	2014		2013
Millions
Trade Accounts Receivable
Billed		$85.5		$78.7
Unbilled	18.6		18.7
Less: Allowance for Doubtful Accounts	1.1		1.1
Total Accounts Receivable		$103.0		$96.3

Inventories [Table Text Block]

Inventories. Inventories are stated at the lower of cost or market. Amounts removed from inventory are recorded on an average cost basis.

Inventories
As of December 31	2014		2013
Millions
Fuel (a)		$29.0		$13.1
Materials and Supplies	51.5		46.2
Total Inventories		$80.5		$59.3

(a) Fuel inventory was lower at December 31, 2013 primarily due to the timing of coal shipments.

Prepayments and Other Current Assets [Table Text Block]

Prepayments and Other Current Assets
As of December 31	2014		2013
Millions
Deferred Fuel Adjustment Clause		$16.3		$23.0
Construction Costs for Development Project (a)	48.2		—
Restricted Cash (b)	2.7		—
Other	14.8		12.1
Total Prepayments and Other Current Assets		$82.0		$35.1

(a) Construction Costs for Development Project acquired/incurred due to ALLETE Clean Energy’s acquisition on November 20, 2014 of a project to develop and construct a wind energy facility in 2015. (See Other Current Liabilities table and Note 7. Acquisitions.)

(b) Restricted Cash related to ALLETE Clean Energy’s wind energy facilities operating expense and capital distribution reserve requirements.

Other Current and Non-Current Liabilities [Table Text Block]

Other Current Liabilities
As of December 31	2014		2013
Millions
Customer Deposits		$19.7		$26.0
Power Purchase Agreements (a)	19.4		—
Construction Deposits Received for Development Project (b)	54.3		—
Other	27.4		26.6
Total Other Current Liabilities		$120.8		$52.6

(a) Power Purchase Agreements were acquired in conjunction with the ALLETE Clean Energy wind energy facilities acquisitions in 2014. (See Note 7. Acquisitions.)

(b) Construction Deposits Received for Development Project are due to ALLETE Clean Energy’s project to develop and construct a wind energy facility in 2015. (See Prepayment and Other Current Assets table and Note 7. Acquisitions.)

Other Non-Current Liabilities
As of December 31	2014		2013
Millions
Asset Retirement Obligation (a)		$109.2		$81.8
Power Purchase Agreements (b)	110.7		—
Other	45.1		45.4
Total Other Non-Current Liabilities		$265.0		$127.2

(a) The increase in 2014 is primarily related to BNI Coal for coal mining expansion and ALLETE Clean Energy due to wind energy facilities acquisitions.

(b) Power Purchase Agreements were acquired in conjunction with the ALLETE Clean Energy wind energy facilities acquisitions in 2014. (See Note 7. Acquisitions.)