Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

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The percentage rate used to calculate dividend payments on preferred stock.

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- Definition

Amount of consolidated retained earnings that represent undistributed (not yet received) earnings from 50% or less owned persons accounted for by the equity method (equity method investees).

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-Name Accounting Standards Codification
-Topic 852
-SubTopic 20
-Section 50
-Paragraph 2
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- Definition

Represents the common equity ratio which is required to be maintained

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Represents the percentage of common stockholders equity to total capitalization used as a threshold for dividend payment restrictions.

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Represents the number of periods for which interest payments on junior subordinated notes can be deferred.

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- Definition

Represents the maximum debt to capitalization ratio.

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Represents the number of consecutive years for which interest payments on junior subordinated notes can be deferred.

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- Definition

Percentage of net income for which dividends can be declared if certain common stock equity to total capitalization ratios are not maintained.

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- Definition

[Line Items] for Schedule itemizing dividend payment restrictions imposed by regulatory authorities.

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Common Equity - Dividend Restrictions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) period	Dec. 31, 2018
Dividend Payment Restrictions [Line Items]
Junior notes minimum interest deferral payment period (in periods) \| period	1
Junior notes maximum interest payment deferral period (in years)	10 years
Restricted net assets of consolidated subsidiaries	$ 7,400
Undistributed earnings of investees accounted for by the equity method	$ 363
WE
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio	65.00%
WE \| 3.60% Serial Preferred Stock
Dividend Payment Restrictions [Line Items]
Dividend rate (as a percent)	3.60%	3.60%
WE \| 3.60% Serial Preferred Stock \| Minimum \| Common stock equity to total capitalization is between 25% and 20%
Dividend Payment Restrictions [Line Items]
Percentage of common equity to total capitalization required to be maintained	20.00%
WE \| 3.60% Serial Preferred Stock \| Maximum \| Common stock equity to total capitalization is between 25% and 20%
Dividend Payment Restrictions [Line Items]
Percentage of net income for which dividends can be declared	75.00%
Percentage of common equity to total capitalization required to be maintained	25.00%
WE \| 3.60% Serial Preferred Stock \| Maximum \| Common stock equity to total capitalization is less than 20%
Dividend Payment Restrictions [Line Items]
Percentage of net income for which dividends can be declared	50.00%
Percentage of common equity to total capitalization required to be maintained	20.00%
WE \| Public Service Commission of Wisconsin \| Minimum
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	52.50%
WPS
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio	65.00%
WPS \| Public Service Commission of Wisconsin \| Minimum
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	52.50%
WG \| Public Service Commission of Wisconsin \| Minimum
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	52.50%
UMERC
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio	65.00%
ATC Holding LLC
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio	65.00%
Bluewater Gas Storage, LLC
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio	65.00%