Amount of liability for consideration received or receivable from customer which is not included in transaction price, when consideration is expected to be refunded to customer, classified as current.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 55
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=118944142&loc=SL49130611-203046-203046

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Percentage of public utility's approved equity to capital, including debt and equity.

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Amount of public utility's approved rate increase (decrease) by regulatory agency.

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Percentage of public utility's approved return on equity.

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Amount of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

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Percentage of public utility's requested rate increase (decrease) with regulatory agency.

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Percentage of public utility's requested return on equity.

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The amount of regulated other operating revenues recognized during the period.

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Regulatory Matters - Electric Rates (Details) - Retail Customers [Member] - USD ($) $ in Millions				9 Months Ended
	Nov. 01, 2019	Dec. 20, 2018	Jan. 18, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
PSCW [Member] \| 2018 Wisconsin General Rate Case [Member] \| SWL&P [Member]
Regulatory Matters [Line Items]
Approved Return on Common Equity		10.40%
Approved Equity Ratio		55.00%
Approved Rate Increase Amount		$ 1.3
Electric Rates [Member] \| MPUC [Member] \| Minnesota Cost Recovery Riders [Member] \| Minnesota Power [Member]
Regulatory Matters [Line Items]
Revenue from Cost Recovery Riders				$ 24.3	$ 81.2
Electric Rates [Member] \| MPUC [Member] \| 2016 Minnesota General Rate Case [Member] \| Minnesota Power [Member]
Regulatory Matters [Line Items]
Approved Return on Common Equity			9.25%
Approved Equity Ratio			53.81%
Annual Additional Revenue Generated from Requested Final Rate Increase			$ 13.0
Reserve for Interim Rate Refund						$ 40.0
Subsequent Event [Member] \| Electric Rates [Member] \| MPUC [Member] \| 2020 Minnesota General Rate Review [Member] \| Minnesota Power [Member]
Regulatory Matters [Line Items]
Annual Additional Revenue Generated from Requested Final Rate Increase	$ 66.0
Requested Rate Increase Percent	10.60%
Interim Rate Increase	$ 48.0
Requested Return on Equity	10.05%
Requested Equity Capital Structure	53.81%