Investment in Transmission Affiliates (Tables)

12 Months Ended

Dec. 31, 2021

Equity Method Investments and Joint Ventures [Abstract]

Schedule of changes to our investments in ATC and ATC Holdco

The following tables provide a reconciliation of the changes in our investments in ATC and ATC Holdco:

	2021
(in millions)	ATC		ATC Holdco		Total
Balance at January 1	$	1,733.5	$	30.8	$	1,764.3
Add: Earnings (loss) from equity method investment	166.4		(8.3)		158.1
Less: Distributions	133.0		—		133.0
Balance at December 31	$	1,766.9	$	22.5	$	1,789.4

	2020
(in millions)	ATC		ATC Holdco		Total
Balance at January 1	$	1,684.7	$	36.1	$	1,720.8
Add: Earnings from equity method investment	174.3		1.5		175.8
Add: Capital contributions	21.2		—		21.2
Less: Distributions	146.7		—		146.7
Less: Return of capital	—		6.8		6.8
Balance at December 31	$	1,733.5	$	30.8	$	1,764.3

	2019
(in millions)	ATC		ATC Holdco		Total
Balance at January 1	$	1,625.3	$	40.0	$	1,665.3
Add: Earnings (loss) from equity method investment	132.8		(5.2)		127.6
Add: Capital contributions	51.3		1.3		52.6
Less: Distributions	124.7		—		124.7
Balance at December 31	$	1,684.7	$	36.1	$	1,720.8

Schedule of significant related party transactions with ATC

The following table summarizes our significant related party transactions with ATC during the years ended December 31:

(in millions)	2021		2020		2019
Charges to ATC for services and construction	$	22.9	$	27.5	$	25.9
Charges from ATC for network transmission services	361.0		350.5		348.1
Net refund from ATC related to FERC ROE orders	7.3		10.7		—

Schedule of receivables and payables with ATC

As of December 31, 2021 and 2020, our balance sheets included the following receivables and payables for services provided to or received from ATC:

(in millions)	2021		2020
Accounts receivable for services provided to ATC	$	2.0	$	3.7
Accounts payable for services received from ATC	30.2		29.3
Amounts due from ATC for transmission infrastructure upgrades (1)	13.0		4.6

(1)    The transmission infrastructure upgrades were primarily related to WE's and WPS's construction of their new solar projects, Badger Hollow II and Badger Hollow I, respectively.

Schedule of summarized income statement data for ATC

Summarized financial data for ATC is included in the tables below:

	Year Ended December 31
(in millions)	2021		2020		2019
Income statement data
Operating revenues	$	754.8	$	758.1	$	744.4
Operating expenses	376.2		372.5		373.5
Other expense, net	113.9		110.8		110.5
Net income	$	264.7	$	274.8	$	260.4

Schedule of summarized balance sheet data for ATC

(in millions)	December 31, 2021		December 31, 2020
Balance sheet data
Current assets	$	89.8	$	92.7
Noncurrent assets	5,628.1		5,400.6
Total assets	$	5,717.9	$	5,493.3
Current liabilities	$	436.9	$	310.8
Long-term debt	2,513.0		2,512.2
Other noncurrent liabilities	422.0		378.2
Members' equity	2,346.0		2,292.1
Total liabilities and members' equity	$	5,717.9	$	5,493.3