Operations and Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2021

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	September 30, 2021	December 31, 2020	September 30, 2020	December 31, 2019
Millions
Cash and Cash Equivalents	$59.0	$44.3	$79.0	$69.3
Restricted Cash included in Prepayments and Other	4.1	0.8	3.2	2.8
Restricted Cash included in Other Non-Current Assets	2.3	20.1	2.9	20.4
Cash, Cash Equivalents and Restricted Cash on the Consolidated Statement of Cash Flows	$65.4	$65.2	$85.1	$92.5

Inventories – Net [Table Text Block]

Inventories – Net	September 30, 2021	December 31, 2020
Millions
Fuel (a)	$12.4	$23.1
Materials and Supplies	55.2	51.1
Construction of Wind Energy Facilities (b)	22.0	—
Total Inventories – Net	$89.6	$74.2

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

(b) Project costs related to ALLETE Clean Energy’s Northern Wind and Red Barn wind projects which are expected be sold in late 2022. (See Other Current Liabilities.)

Other Non-Current Assets [Table Text Block]

Other Non-Current Assets	September 30, 2021	December 31, 2020
Millions
Contract Assets (a)	$23.4	$25.5
Operating Lease Right-of-use Assets	17.7	22.4
ALLETE Properties	17.6	18.2
Restricted Cash	2.3	20.1
Other Postretirement Benefit Plans	35.8	34.2
Other	82.9	86.4
Total Other Non-Current Assets	$179.7	$206.8

(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	September 30, 2021	December 31, 2020
Millions
Customer Deposits (a)	$27.5	$7.4
PSAs	12.6	12.5
Fuel Adjustment Clause	2.6	3.7
Operating Lease Liabilities	5.0	5.9
Other	36.3	37.2
Total Other Current Liabilities	$84.0	$66.7

(a) Primarily related to deposits received by ALLETE Clean Energy for the Northern Wind and Red Barn wind projects which are expected be sold in late 2022. (See Inventories – Net.)

Other Non-Current Liabilities [Table Text Block]

Other Non-Current Liabilities	September 30, 2021	December 31, 2020
Millions
Asset Retirement Obligation (a)	$170.9	$166.6
PSAs	42.6	52.1
Operating Lease Liabilities	12.7	16.5
Other	51.9	50.1
Total Other Non-Current Liabilities	$278.1	$285.3

(a)The asset retirement obligation is primarily related to our Regulated Operations and is funded through customer rates over the life of the related assets. Additionally, BNI Energy funds its obligation through its cost-plus coal supply agreements for which BNI Energy has recorded a receivable of $25.0 million in Other Non-Current Assets on the Consolidated Balance Sheet as of September 30, 2021, and December 31, 2020.

Other Income [Table Text Block]

Other Income
Nine Months Ended September 30,	2021	2020
Millions
Pension and Other Postretirement Benefit Plan Non-Service Credits (a)	$4.4	$6.5
Interest and Investment Income	1.7	0.4
AFUDC - Equity	1.7	1.8
Other	(1.7)	0.4
Total Other Income	$6.1	$9.1

(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.

Nine Months Ended September 30,	2021	2020
Millions
Cash Paid for Interest – Net of Amounts Capitalized	$54.9	$48.8
Noncash Investing and Financing Activities
Increase in Accounts Payable for Capital Additions to Property, Plant and Equipment	$(12.1)	$(88.4)
Capitalized Asset Retirement Costs	$3.5	$2.1
AFUDC–Equity	$1.7	$1.8