Business Segment (Tables)

12 Months Ended

Dec. 31, 2021

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

Year Ended December 31	2021	2020	2019
Millions
Operating Revenue
Residential	$160.8	$140.7	$139.6
Commercial	168.6	139.5	145.7
Municipal	52.0	41.2	48.6
Industrial	565.5	432.8	476.4
Other Power Suppliers	168.7	138.8	153.7
CIP Financial Incentive (a)	2.4	2.4	2.8
Other	109.9	91.9	75.6
Total Regulated Operations	1,227.9	987.3	1,042.4
ALLETE Clean Energy
Long-term PSA	75.5	68.3	48.0
Other	11.4	11.3	11.6
Total ALLETE Clean Energy	86.9	79.6	59.6
U.S. Water Services (b)
Point-in-time	—	—	19.0
Contract	—	—	9.2
Capital Project	—	—	5.2
Total U.S. Water Services	—	—	33.4
Corporate and Other
Long-term Contract	84.4	86.0	82.8
Other	20.0	16.2	22.3
Total Corporate and Other	104.4	102.2	105.1
Total Operating Revenue	$1,419.2	$1,169.1	$1,240.5
Net Income (Loss) Attributable to ALLETE (c)
Regulated Operations	$129.1	$136.3	$154.4
ALLETE Clean Energy	26.3	29.9	12.4
U.S. Water Services	—	—	(1.1)
Corporate and Other (b)(d)	13.8	8.0	19.9
Total Net Income Attributable to ALLETE	$169.2	$174.2	$185.6

(a)    See Note 4. Regulatory Matters.

(b)     In 2019, ALLETE sold U.S. Water Services. The Company recognized a gain on the sale of $13.2 million after-tax which is reflected in Corporate and Other. (See Note 1. Operations and Significant Accounting Policies.)

(c)    Includes interest expense resulting from intercompany loan agreements and allocated to certain subsidiaries. The amounts are eliminated in consolidation. 

(d)    In 2021, South Shore Energy sold a portion of its undivided ownership interest in NTEC to Basin. The closing of the transaction resulted in the recognition of an approximately $8.5 million after-tax gain which is reflected in Corporate and Other. (See Note 1. Operations and Significant Accounting Policies.)

Year Ended December 31	2021	2020	2019
Millions
Depreciation and Amortization
Regulated Operations	$170.7	$166.9	$159.4
ALLETE Clean Energy	49.2	37.9	26.8
U.S. Water Services	—	—	2.3
Corporate and Other	11.8	13.0	13.5
Total Depreciation and Amortization	$231.7	$217.8	$202.0
Interest Expense (a)
Regulated Operations	$57.3	$58.5	$58.9
ALLETE Clean Energy	1.5	2.2	2.8
U.S. Water Services	—	—	0.2
Corporate and Other	13.2	13.2	8.0
Eliminations	(2.9)	(8.3)	(5.0)
Total Interest Expense	$69.1	$65.6	$64.9
Equity Earnings
Regulated Operations	$21.3	$22.3	$21.7
Corporate and Other	(1.3)	(0.2)	—
Total Equity Earnings	$20.0	$22.1	$21.7
Income Tax Expense (Benefit)
Regulated Operations	$(16.6)	$(19.4)	$(7.1)
ALLETE Clean Energy	(16.6)	(19.1)	(11.9)
U.S. Water Services	—	—	(0.4)
Corporate and Other (b)	6.3	(1.0)	12.8
Total Income Tax Benefit	$(26.9)	$(39.5)	$(6.6)

(a)    Includes interest expense resulting from intercompany loan agreements and allocated to certain subsidiaries. The amounts are eliminated in consolidation.    

(b) In 2019, ALLETE sold U.S. Water Services. The Company recognized income tax expense of $10.4 million for the gain on sale of U.S. Water Services which is reflected in Corporate and Other. (See Note 1. Operations and Significant Accounting Policies.)

As of December 31	2021	2020
Millions
Assets
Regulated Operations	$4,289.4	$4,196.8
ALLETE Clean Energy	1,719.4	1,483.3
Corporate and Other	426.2	404.5
Total Assets	$6,435.0	$6,084.6
Capital Expenditures
Regulated Operations	$166.8	$133.7
ALLETE Clean Energy	269.9	507.8
Corporate and Other	39.7	15.7
Total Capital Expenditures	$476.4	$657.2