Operations and Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Cash, Cash Equivalents and Restricted Cash [Table Text Block]

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheet that aggregate to the amounts presented in the Consolidated Statement of Cash Flows.

Cash, Cash Equivalents and Restricted Cash	March 31, 2020		December 31, 2019		March 31, 2019		December 31, 2018
Millions
Cash and Cash Equivalents		$67.0		$69.3		$353.3		$69.1
Restricted Cash included in Prepayments and Other	6.1		2.8		7.2		1.3
Restricted Cash included in Other Non-Current Assets	5.8		20.4		4.7		8.6
Cash, Cash Equivalents and Restricted Cash on the Consolidated Statement of Cash Flows		$78.9		$92.5		$365.2		$79.0

Inventories – Net [Table Text Block]

Inventories – Net	March 31, 2020		December 31, 2019
Millions
Fuel (a)		$31.4		$25.9
Materials and Supplies	47.6		46.9
Total Inventories – Net		$79.0		$72.8

(a) Fuel consists primarily of coal inventory at Minnesota Power.

Other Non-Current Assets	March 31, 2020		December 31, 2019
Millions
Contract Assets (a)		$27.3		$28.0
Operating Lease Right-of-use Assets	26.8		28.6
ALLETE Properties	21.5		21.9
Restricted Cash	5.8		20.4
Other Postretirement Benefit Plans	38.0		37.5
Other	79.5		81.8
Total Other Non-Current Assets		$198.9		$218.2

Other Non-Current Assets [Table Text Block]

Other Non-Current Assets	March 31, 2020		December 31, 2019
Millions
Contract Assets (a)		$27.3		$28.0
Operating Lease Right-of-use Assets	26.8		28.6
ALLETE Properties	21.5		21.9
Restricted Cash	5.8		20.4
Other Postretirement Benefit Plans	38.0		37.5
Other	79.5		81.8
Total Other Non-Current Assets		$198.9		$218.2

(a) Contract Assets consist of payments made to customers as an incentive to execute or extend service agreements. The contract payments are being amortized over the term of the respective agreements as a reduction to revenue.     

Other Current Liabilities [Table Text Block]

Other Current Liabilities	March 31, 2020		December 31, 2019
Millions
PSAs		$12.4		$12.3
Operating Lease Liabilities	6.9		6.9
Other	38.3		41.2
Total Other Current Liabilities		$57.6		$60.4

Other Non-Current Liabilities [Table Text Block]

Other Non-Current Liabilities	March 31, 2020		December 31, 2019
Millions
Asset Retirement Obligation		$163.2		$160.3
PSAs	61.5		64.6
Operating Lease Liabilities	20.0		21.8
Other	44.0		46.3
Total Other Non-Current Liabilities		$288.7		$293.0

Other Income [Table Text Block]

Other Income
Three Months Ended March 31,	2020			2019
Millions
Pension and Other Postretirement Benefit Plan Non-Service Credits (a)		$2.6			$2.0
Interest and Investment Income (Loss)	(2.6		)	1.0
AFUDC - Equity	0.5			0.6
Gain on Land Sales	0.1			1.8
Other	0.4			2.0
Total Other Income		$1.0			$7.4

(a)

These are components of net periodic pension and other postretirement benefit cost other than service cost. (See Note 9. Pension and Other Postretirement Benefit Plans.)

Supplemental Statement of Cash Flows Information [Table Text Block]

Supplemental Statement of Cash Flows Information.

Three Months Ended March 31,	2020		2019
Millions
Cash Paid for Interest – Net of Amounts Capitalized		$18.3		$19.7
Recognition of Right-of-use Assets and Lease Liabilities	—			$34.0
Noncash Investing and Financing Activities
Increase (Decrease) in Accounts Payable for Capital Additions to Property, Plant and Equipment	$4.7		$(1.1)
Capitalized Asset Retirement Costs		$1.6		$1.6
AFUDC–Equity		$0.5		$0.6